Opththalmic devices comprising polyester compositions formed from 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1,4-cyclohexanedimethanol

ABSTRACT

Described are ophthalmic products comprising polyester compositions comprising polyesters which comprise (a) a dicarboxylicacid component having terephthalic acid residues; optionally, aromatic dicarboxylic acid residues or aliphatic dicarboxylic acid residues or ester residues thereof; 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and 1,4-cyclohexanedimethanol residues.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) to U.S.Provisional Application Ser. No. 60/691,567 filed on Jun. 17, 2005, U.S.Provisional Application Ser. No. 60/731,454 filed on Oct. 28, 2005, U.S.Provisional Application Ser. No. 60/731,389, filed on Oct. 28, 2005,U.S. Provisional Application Ser. No. 60/739,058, filed on Nov. 22,2005, and U.S. Provisional Application Ser. No. 60/738,869, filed onNov. 22, 2005, U.S. Provisional Application Ser. No. 60/750,692 filed onDec. 15, 2005, U.S. Provisional Application Ser. No. 60/750,693, filedon Dec. 15, 2005, U.S. Provisional Application Ser. No. 60/750,682,filed on Dec. 15, 2005, and U.S. Provisional Application Ser. No.60/750,547, filed on Dec. 15, 2005, all of which are hereby incorporatedby this reference in their entireties.

FIELD OF THE INVENTION

The present invention generally relates to ophthalmic productscomprising a polyester compositions made from terephthalic acid, or anester thereof, or mixtures thereof,2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 1,4-cyclohexanedimethanol,having a certain combination of two or more of high impact strengths,high glass transition temperature (T_(g)), toughness, certain inherentviscosities, low ductile-to-brittle transition temperatures, good colorand clarity, low densities, chemical resistance, hydrolytic stability,and long crystallization half-times, which allow them to be easilyformed into articles. For example, the ophthalmic products of thepresent invention can have a combination of two or more of the followingproperties: toughness, clarity, chemical resistance (e.g., forwithstanding lens cleaners, oils, hair products, etc.), Tg, andhydrolytic stability.

BACKGROUND OF THE INVENTION

Ophthalmic products can be produced with a variety of plastic materialsby a variety of processes, such as injection molding. Polycarbonates arewidely used in a variety of molding and extrusion applications.

Poly(1,4-cyclohexylenedimethylene)terephthalate (PCT), a polyester basedsolely on terephthalic acid or an ester thereof and1,4-cyclohexanedimethanol, is known in the art and is commerciallyavailable. This polyester crystallizes rapidly upon cooling from themelt, making it very difficult to form amorphous articles by methodsknown in the art such as extrusion, injection molding, and the like. Inorder to slow down the crystallization rate of PCT, copolyesters can beprepared containing additional dicarboxylic acids or glycols such asisophthalic acid or ethylene glycol. These ethylene glycol- orisophthalic acid-modified PCTs are also known in the art and arecommercially available.

One common copolyester used to produce films, sheeting, and moldedarticles is made from terephthalic acid, 1,4-cyclohexanedimethanol, andethylene glycol. While these copolyesters are useful in many end-useapplications, they exhibit deficiencies in properties such as glasstransition temperature and impact strength when sufficient modifyingethylene glycol is included in the formulation to provide for longcrystallization half-times. For example, copolyesters made fromterephthalic acid, 1,4-cyclohexanedimethanol, and ethylene glycol withsufficiently long crystallization half-times can provide amorphousproducts that exhibit what is believed to be undesirably higherductile-to-brittle transition temperatures and lower glass transitiontemperatures than the compositions revealed herein.

The polycarbonate of 4,4′-isopropylidenediphenol (bisphenol Apolycarbonate) has been used as an alternative for polyesters known inthe art and is a well known engineering molding plastic. Bisphenol Apolycarbonate is a clear, high-performance plastic having good physicalproperties such as dimensional stability, high heat resistance, and goodimpact strength. Although bisphenol-A polycarbonate has many goodphysical properties, its relatively high melt viscosity leads to poormelt processability and the polycarbonate exhibits poor chemicalresistance. It is also difficult to thermoform.

Polymers containing 2,2,4,4-tetramethyl-1,3-cyclobutanediol have alsobeen generally described in the art. Generally, however, these polymersexhibit high inherent viscosities, high melt viscosities and/or high Tgs(glass transition temperatures) such that the equipment used in industrycan be insufficient to manufacture or post polymerization process thesematerials.

Thus, there is a need in the art for ophthalmic products comprising atleast one polymer having a combination of two or more properties, chosenfrom at least one of the following: toughness, high glass transitiontemperatures, high impact strength, hydrolytic stability, chemicalresistance, long crystallization half-times, low ductile to brittletransition temperatures, good color, and clarity, lower density and/orthermoformability of polyesters while retaining processability on thestandard equipment used in the industry.

SUMMARY OF THE INVENTION

It is believed that certain ophthalmic products comprising polyestercompositions formed from terephthalic acid, an ester thereof, ormixtures thereof, 1,4-cyclohexanedimethanol and2,2,4,4-tetramethyl-1,3-cyclobutanediol with certain monomercompositions, inherent viscosities and/or glass transition temperaturesare superior to polyesters known in the art and to polycarbonate withrespect to one or more of high impact strengths, hydrolytic stability,toughness, chemical resistance, good color and clarity, longcrystallization half-times, low ductile to brittle transitiontemperatures, lower specific gravity, and thermoformability. Thesecompositions are believed to be similar to polycarbonate in heatresistance and are still processable on the standard industry equipment.

In one aspect, the invention relates to an ophthalmic product comprisingat least one polyester composition comprising at least one polyester,which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 10 to 99 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 1 to 90 mole % of 1,4-cyclohexanedimethanol residues,        wherein the total mole % of the dicarboxylic acid component is        100 mole %, the total mole % of the glycol component is 100 mole        %; and

wherein the inherent viscosity of the polyester is from 0.1 to 1.2 dL/gas determined in 60/40 (wt/wt) phenol/tetrachloroethane at aconcentration of 0.5 g/100 ml at 25° C.; and

wherein the polyester has a Tg of from 100 to 200° C.

In one aspect, the invention relates to an ophthalmic product comprisingat least one polyester composition comprising at least one polyester,which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 15 to 70 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 30 to 85 mole % of 1,4-cyclohexanedimethanol residues,        wherein the total mole % of the dicarboxylic acid component is        100 mole %, the total mole % of the glycol component is 100 mole        %; and

wherein the inherent viscosity of the polyester is from 0.35 to 1.2 dL/gas determined in 60/40 (wt/wt) phenol/tetrachloroethane at aconcentration of 0.5 g/l 00 ml at 25° C.; and

wherein the polyester has a Tg of from 100 to 160° C.

In one aspect, the invention relates to an ophthalmic product comprisingat least one polyester composition comprising at least one polyester,which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 20 to 40 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 60 to 80 mole % of 1,4-cyclohexanedimethanol residues,

wherein the total mole % of the dicarboxylic acid component is 100 mole%, the total mole % of the glycol component is 100 mole %; and

wherein the inherent viscosity of the polyester is from 0.35 to 0.75dL/g as determined in 60/40 (wt/wt) phenol/tetrachloroethane at aconcentration of 0.5 g/100 ml at 25° C.; and

wherein the polyester has a Tg of from 100 to 120° C.

In one aspect, the invention relates to an ophthalmic product comprisingat least one polyester composition comprising at least one polyester,which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 40 to 55 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 45 to 60 mole % of 1,4-cyclohexanedimethanol residues,        wherein the total mole % of the dicarboxylic acid component is        100 mole %, the total mole % of the glycol component is 100 mole        %; and

wherein the inherent viscosity of the polyester is from 0.35 to 0.75dL/g as determined in 60/40 (wt/wt) phenol/tetrachloroethane at aconcentration of 0.5 g/100 ml at 25° C.; and

wherein the polyester has a Tg of from 120 to 140° C.

In one aspect, the invention relates to an ophthalmic product comprisingat least one polyester composition comprising at least one polyester,which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 15 to 70 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 30 to 85 mole % of 1,4-cyclohexanedimethanol residues,        wherein the total mole % of the dicarboxylic acid component is        100 mole %, the total mole % of the glycol component is 100 mole        %; and

wherein the inherent viscosity of the polyester is from 0.35 to 0.75dL/g as determined in 60/40 (wt/wt) phenol/tetrachloroethane at aconcentration of 0.5 g/100 ml at 25° C.; and

wherein the polyester has a Tg of from 100 to 140° C.

In one aspect, the invention relates to an ophthalmic product comprisingat least one polyester composition comprising at least one polyester,which comprises:

(a) a dicarboxylic acid component comprising:

-   -   i) 70 to 100 mole % of terephthalic acid residues;    -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues having        up to 20 carbon atoms; and    -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues        having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 15 to 90 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 10 to 85 mole % of 1,4-cyclohexanedimethanol residues,        wherein the total mole % of the dicarboxylic acid component is        100 mole %, the total mole % of the glycol component is 100 mole        %; and

wherein the inherent viscosity of the polyester is from 0.1 to 1.2 dL/gas determined in 60/40 (wt/wt) phenol/tetrachloroethane at aconcentration of 0.5 g/l 00 ml at 25° C.; and

wherein the polyester has a Tg of from 100 to 200° C.

In one aspect, the invention relates to an ophthalmic product comprisingat least one polyester composition comprising at least one polyester,which comprises:

(I) at least one polyester which comprises:

-   -   (a) a dicarboxylic acid component comprising:        -   i) 70 to 100 mole % of terephthalic acid residues;        -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues            having up to 20 carbon atoms; and        -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues            having up to 16 carbon atoms; and    -   (b) a glycol component comprising:        -   i) 10 to 99 mole % of            2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and        -   ii) 1 to 90 mole % of 1,4-cyclohexanedimethanol residues,            and

(II) residues of at least one branching agent;

wherein the total mole % of the dicarboxylic acid component is 100 mole%, the total mole % of the glycol component is 100 mole %; and

wherein the inherent viscosity of the polyester is from 0.1 to 1.2 dL/gas determined in 60/40 (wt/wt) phenol/tetrachloroethane at aconcentration of 0.5 g/100 ml at 25° C.; and

wherein the polyester has a Tg of from 100 to 200° C.

In one aspect, the invention relates to an ophthalmic product comprisingat least one polyester composition comprising at least one polyester,which comprises:

(I) at least one polyester which comprises:

-   -   (a) a dicarboxylic acid component comprising:        -   i) 70 to 100 mole % of terephthalic acid residues;        -   ii) 0 to 30 mole % of aromatic dicarboxylic acid residues            having up to 20 carbon atoms; and        -   iii) 0 to 10 mole % of aliphatic dicarboxylic acid residues            having up to 16 carbon atoms; and

(b) a glycol component comprising:

-   -   i) 10 to 99 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol        residues; and    -   ii) 1 to 90 mole % of 1,4-cyclohexanedimethanol residues, and

(II) at least one thermal stabilizer or reaction products thereof;

wherein the total mole % of the dicarboxylic acid component is 100 mole%, the total mole % of the glycol component is 100 mole %; and

wherein the inherent viscosity of the polyester is from 0.1 to 1.2 dL/gas determined in 60/40 (wt/wt) phenol/tetrachloroethane at aconcentration of 0.5 g/100 ml at 25° C.; and

wherein the polyester has a Tg of from 100 to 200° C.

In one aspect, the polyester composition contains at least onepolycarbonate.

In one aspect, the polyester composition contains no polycarbonate.

In one aspect, the polyesters useful in the invention contain less than15 mole % ethylene glycol residues, such as, for example, 0.01 to lessthan 15 mole % ethylene glycol residues.

In one aspect, the polyesters useful in the invention contain noethylene glycol residues.

In one aspect the polyester compositions useful in the invention containat least one thermal stabilizer and/or reaction products thereof.

In one aspect, the polyesters useful in the invention contain nobranching agent, or alternatively, at least one branching agent is addedeither prior to or during polymerization of the polyester.

In one aspect, the polyesters useful in the invention contain at leastone branching agent without regard to the method or sequence in which itis added.

In one aspect, the polyesters useful in the invention are made from no1,3-propanediol, or, 1,4-butanediol, either singly or in combination. Inother aspects, 1,3-propanediol or 1,4-butanediol, either singly or incombination, may be used in the making of the polyesters useful in thisinvention.

In one aspect of the invention, the mole % ofcis-2,2,4,4-tetramethyl-1,3-cyclobutanediol useful in certain polyestersuseful in the invention is greater than 50 mole % or greater than 55mole % of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol or greater than 70mole % of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol; wherein the totalmole percentage of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol andtrans-2,2,4,4-tetramethyl-1,3-cyclobutanediol is equal to a total of 100mole %.

In one aspect of the invention, the mole % of the isomers of2,2,4,4-tetramethyl-1,3-cyclobutanediol useful in certain polyestersuseful in the invention is from 30 to 70 mole % ofcis-2,2,4,4-tetramethyl-1,3-cyclobutanediol or from 30 to 70 mole % oftrans-2,2,4,4-tetramethyl-1,3-cyclobutanediol, or from 40 to 60 mole %of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol or from 40 to 60 mole %of trans-2,2,4,4-tetramethyl-1,3-cyclobutanediol, wherein the total molepercentage of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol andtrans-2,2,4,4-tetramethyl-1,3-cyclobutanediol is equal to a total of 100mole %.

In one aspect, the polyester compositions are useful in ophthalmicproduct(s) including, but not limited to, extruded and/or moldedarticles including but not limited to, injection molded articles,extruded articles, cast extrusion articles,.

Also, in one aspect, use of the polyester compositions of the inventionminimizes and/or eliminates the drying step prior to melt processing orthermoforming.

In one aspect, certain polyesters useful in the invention can beamorphous or semicrystalline. In one aspect, certain polyesters usefulin the invention can have a relatively low crystallinity. Certainpolyesters useful in the invention can thus have a substantiallyamorphous morphology, meaning that the polyesters comprise substantiallyunordered regions of polymer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the effect of comonomer on the fastestcrystallization half-times of modified PCT copolyesters.

FIG. 2 is a graph showing the effect of comonomer on thebrittle-to-ductile transition temperature (T_(bd)) in a notched Izodimpact strength test (ASTM D256, ⅛-in thick, 10-mil notch).

FIG. 3 is a graph showing the effect of2,2,4,4-tetramethyl-1,3-cyclobutanediol composition on the glasstransition temperature (Tg) of the copolyester.

DETAILED DESCRIPTION OF THE INVENTION

The present invention may be understood more readily by reference to thefollowing detailed description of certain embodiments of the inventionand the working examples.

In accordance with the purpose(s) of this invention, certain embodimentsof the invention are described in the Summary of the Invention and arefurther described herein below. Also, other embodiments of the inventionare described herein.

It is believed that the polyester(s) and/or polyester composition(s)which are included in the ophthalmic product(s) of the inventiondescribed herein can have a unique combination of two or more physicalproperties such as high impact strengths, moderate to high glasstransition temperatures, chemical resistance, hydrolytic stability,toughness, low ductile-to-brittle transition temperatures, good colorand clarity, low densities, long crystallization half-times, and goodprocessability thereby easily permitting them to be formed intoarticles. In some of the embodiments of the invention, the polyestershave a unique combination of the properties of good impact strength,heat resistance, chemical resistance, density and/or the combination ofthe properties of good impact strength, heat resistance, andprocessability and/or the combination of two or more of the describedproperties, that have never before been believed to be present inophthalmic product(s) comprising the polyester compositions whichcomprise the polyester(s) as disclosed herein.

“Ophthalmic product” as used herein, refers to prescription eyeglasslenses, nonprescription eyeglass lenses, sunglass lenses, and eyeglassand sunglass frames.

In one embodiment, the ophthalmic product is chosen from tinted eyeglasslenses and hardcoated eyeglass lenses. In one embodiment, the eyeglasslenses, such as the tinted eyeglass lenses or hardcoated eyeglasslenses, comprise at least one polarizing film or polarizing additive.

In one embodiment, when the product is a lens, the ophthalmic producthas a refractive index ranging from 1.54 to 1.56.

In one embodiment, the ophthalmic product can have at least one propertychosen from toughness, clarity, chemical resistance (e.g., forwithstanding lens cleaners, oils, hair products, etc.), Tg, andhydrolytic stability.

The term “polyester”, as used herein, is intended to include“copolyesters” and is understood to mean a synthetic polymer prepared bythe reaction of one or more difunctional carboxylic acids and/ormultifunctional carboxylic acids with one or more difunctional hydroxylcompounds and/or multifunctional hydroxyl compounds. Typically thedifunctional carboxylic acid can be a dicarboxylic acid and thedifunctional hydroxyl compound can be a dihydric alcohol such as, forexample, glycols. Furthermore, as used in this application, the term“diacid” or “dicarboxylic acid” includes multifunctional acids, such asbranching agents. The term “glycol” as used in this applicationincludes, but is not limited to, diols, glycols, and/or multifunctionalhydroxyl compounds. Alternatively, the difunctional carboxylic acid maybe a hydroxy carboxylic acid such as, for example, p-hydroxybenzoicacid, and the difunctional hydroxyl compound may be an aromatic nucleusbearing 2 hydroxyl substituents such as, for example, hydroquinone. Theterm “residue”, as used herein, means any organic structure incorporatedinto a polymer through a polycondensation and/or an esterificationreaction from the corresponding monomer. The term “repeating unit”, asused herein, means an organic structure having a dicarboxylic acidresidue and a diol residue bonded through a carbonyloxy group. Thus, forexample, the dicarboxylic acid residues may be derived from adicarboxylic acid monomer or its associated acid halides, esters, salts,anhydrides, or mixtures thereof. As used herein, therefore, the termdicarboxylic acid is intended to include dicarboxylic acids and anyderivative of a dicarboxylic acid, including its associated acidhalides, esters, half-esters, salts, half-salts, anhydrides, mixedanhydrides, or mixtures thereof, useful in a reaction process with adiol to make polyester. As used herein, the term “terephthalic acid” isintended to include terephthalic acid itself and residues thereof aswell as any derivative of terephthalic acid, including its associatedacid halides, esters, half-esters, salts, half-salts, anhydrides, mixedanhydrides, or mixtures thereof or residues thereof useful in a reactionprocess with a diol to make polyester.

In one embodiment, terephthalic acid may be used as the startingmaterial. In another embodiment, dimethyl terephthalate may be used asthe starting material. In another embodiment, mixtures of terephthalicacid and dimethyl terephthalate may be used as the starting materialand/or as an intermediate material.

The polyesters used in the present invention typically can be preparedfrom dicarboxylic acids and diols which react in substantially equalproportions and are incorporated into the polyester polymer as theircorresponding residues. The polyesters of the present invention,therefore, can contain substantially equal molar proportions of acidresidues (100 mole %) and diol (and/or multifunctional hydroxylcompounds) residues (100 mole %) such that the total moles of repeatingunits is equal to 100 mole %. The mole percentages provided in thepresent disclosure, therefore, may be based on the total moles of acidresidues, the total moles of diol residues, or the total moles ofrepeating units. For example, a polyester containing 30 mole %isophthalic acid, based on the total acid residues, means the polyestercontains 30 mole % isophthalic acid residues out of a total of 100 mole% acid residues. Thus, there are 30 moles of isophthalic acid residuesamong every 100 moles of acid residues. In another example, a polyestercontaining 30 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol, based onthe total diol residues, means the polyester contains 30 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues out of a total of 100mole % diol residues. Thus, there are 30 moles of2,2,4,4-tetramethyl-1,3-cyclobutanediol residues among every 100 molesof diol residues.

In other aspects of the invention, the Tg of the polyesters useful inthe ophthalmic product(s) of the invention can be at least one of thefollowing ranges: 100 to 200° C.; 100 to 190° C.; 100 to 180° C.; 100 to170° C.; 100 to 160° C.; 100 to 155° C.; 100 to 150° C.; 100 to 145° C.;100 to 140° C.; 100 to 138° C.; 100 to 135° C.; 100 to 130° C.; 100 to125° C.; 100 to 120° C.; 100 to 115° C;. 100 to 110° C;. 105 to 200° C.;105 to 190° C.; 105 to 180° C.; 105 to 170° C.; 105 to 160° C.; 105 to155° C.; 105 to 150° C.; 105 to 145° C.; 105 to 140° C.; 105 to 138° C.;105 to 135° C.; 105 to 130° C.; 105 to 125° C.; 105 to 120° C.; 105 to115° C.; 105 to 110° C. greater than 105 to 125° C.; greater than 105 to120° C.; greater than 105 to 115° C.; greater than 105 to 110° C.; 110to 200° C.; 110 to 190° C.; 110 to 180° C.; 110 to 170° C.; 110 to 160°C.; 110 to 155° C.; 110 to 150° C.; 110 to 145° C.; 110 to 140° C.; 110to 138° C.; 110 to 135° C.; 110 to 130° C.; 110 to 125° C.; 110 to 120°C.; 110 to 115° C.; 115to 200° C.; 115 to 190° C.; 115 to 180° C.; 115to 170° C.; 115 to 160° C.; 115to 155° C.; 115 to 150° C.; 115 to 145°C.; 115 to 140° C.; 115 to 138° C.; 115 to 135° C.; 110 to 130° C.; 115to 125° C.; 115 to 120° C.; 120 to 200° C.; 120 to 190° C.; 120 to 180°C.; 120 to 170° C.; 120 to 160° C.; 120 to 155° C.; 120 to 150° C.; 120to 145° C.; 120 to 140° C.; 120 to 138° C.; 120 to 135° C.; 120 to 130°C.; 125 to 200° C.; 125 to 190° C.; 125 to 180° C.; 125 to 170° C.; 125to 160° C; 125 to 155° C.; 125 to 150° C.; 125 to 145° C.; 125 to 140°C.; 125 to 138° C.; 125 to 135° C.; 127 to 200° C.; 127 to 190° C.; 127to 180° C.; 127 to 170° C.; 127 to 160° C.; 127 to 150° C.; 127 to 145°C.; 127 to 140° C.; 127 to 138° C.; 127 to 135° C.; 130 to 200° C.; 130to 190° C.; 130 to 180° C.; 130 to 170° C.; 130 to 160° C.; 130 to 155°C.; 130 to 150° C.; 130 to 145° C.; 130 to 140° C.; 130 to 138° C.; 130to 135° C.; 135 to 200° C.; 135 to 190° C.; 135 to 180° C.; 135 to 170°C.; 135 to 160° C.; 135 to 155° C.; 135 to 150° C.; 135 to 145° C.; 135to 140° C.; 140 to 200° C.; 140 to 190° C; 140 to 180° C.; 140 to 170°C.; 140 to 160° C.; 140 to 155° C.; 140 to 150° C.; 140 to 145° C.; 148to 200° C.; 148 to 190° C.; 148 to 180° C.; 148 to 170° C.; 148 to 160°C.; 148 to 155° C.; 148 to 150° C.; 150 to 200° C.; 150 to 190° C.; 150to 180° C.; 150 to 170° C.; 150 to 160; 155 to 190° C.; 155 to 180° C.;155 to 170° C.; and 155 to 165° C.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 10 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to90 mole % 1,4-cyclohexanedimethanol; 10 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 90 mole %1,4-cyclohexanedimethanol; 10 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 90 mole %1,4-cyclohexanedimethanol; 10 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 90 mole %1,4-cyclohexanedimethanol; 10 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 90 mole %1,4-cyclohexanedimethanol, 10 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 90 mole %1,4-cyclohexanedimethanol; 10 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 90 mole %1,4-cyclohexanedimethanol; 10 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 90 mole %1,4-cyclohexanedimethanol; 10 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to 90 mole %1,4-cyclohexanedimethanol; 10 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to 90 mole %1,4-cyclohexanedimethanol; 10 to 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 50 to 90 mole %1,4-cyclohexanedimethanol; 10 to less than 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and greater than 50 to 90 mole %1,4-cyclohexanedimethanol; 10 to 45 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 55 to 90 mole %1,4-cyclohexanedimethanol; 10 to 40 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 60 to 90 mole %1,4-cyclohexanedimethanol; 10 to 35 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 65 to 90 mole %1,4-cyclohexanedimethanol; 10 to less than 35 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and greater than 65 up to 90mole % 1,4-cyclohexanedimethanol; 10 to 30 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 70 to 90 mole %1,4-cyclohexanedimethanol; 10 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and greater than 75 to 90 mole %1,4-cyclohexanedimethanol; 11 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 89 mole %1,4-cyclohexanedimethanol; 12 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 88 mole %1,4-cyclohexanedimethanol; and 13 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 87 mole %1,4-cyclohexanedimethanol;

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 14 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to86 mole % 1,4-cyclohexanedimethanol; 14 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 86 mole %1,4-cyclohexanedimethanol; 14 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 86 mole %1,4-cyclohexanedimethanol; 14 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 86 mole %1,4-cyclohexanedimethanol; 14 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 86 mole %1,4-cyclohexanedimethanol,14 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 86 mole %1,4-cyclohexanedimethanol; 14 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 86 mole %1,4-cyclohexanedimethanol; 14 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 86 mole %1,4-cyclohexanedimethanol; 14 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to 86 mole %1,4-cyclohexanedimethanol; 14 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to 86 mole %1,4-cyclohexanedimethanol; and 14 to 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 50 to 86 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 14 to less than 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and greater than 50 up to 86mole % 1,4-cyclohexanedimethanol; 14 to 45 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 55 to 86 mole %1,4-cyclohexanedimethanol; 14 to 40 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 60 to 86 mole %1,4-cyclohexanedimethanol; 14 to 35 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 65 to 86 mole %1,4-cyclohexanedimethanol; 14 to 30 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 70 to 86 mole %1,4-cyclohexanedimethanol; and 14 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 86 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 15 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to85 mole % 1,4-cyclohexanedimethanol; 15 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 85 mole %1,4-cyclohexanedimethanol; 15 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 85 mole %1,4-cyclohexanedimethanol; 15 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 85 mole %1,4-cyclohexanedimethanol; 15 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 85 mole %1,4-cyclohexanedimethanol, 15 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 85 mole %1,4-cyclohexanedimethanol; 15 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 85 mole %1,4-cyclohexanedimethanol; 15 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 85 mole %1,4-cyclohexanedimethanol; 15 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to 85 mole %1,4-cyclohexanedimethanol; 15 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to 85 mole %1,4-cyclohexanedimethanol; and 15 to 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 50 to 85 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 15 to less than 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and greater than 50 up to 85mole % 1,4-cyclohexanedimethanol; 15 to 45 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 55 to 85 mole %1,4-cyclohexanedimethanol; 15 to 40 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 60 to 85 mole %1,4-cyclohexanedimethanol; 15 to 35 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 65 to 85 mole %1,4-cyclohexanedimethanol; 15 to 30 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 70 to 85 mole %1,4-cyclohexanedimethanol; 15 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 85 mole %1,4-cyclohexanedimethanol; 15 to 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 80 mole %1,4-cyclohexanedimethanol; and 17 to 23 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 77 to 83 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 20 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to80 mole % 1,4-cyclohexanedimethanol; 20 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 80 mole %1,4-cyclohexanedimethanol; 20 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 80 mole %1,4-cyclohexanedimethanol; 20 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 80 mole %1,4-cyclohexanedimethanol; 20 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 80 mole %1,4-cyclohexanedimethanol, 20 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 80 mole %1,4-cyclohexanedimethanol; 20 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 80 mole %1,4-cyclohexanedimethanol; 20 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 80 mole %1,4-cyclohexanedimethanol; 20 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to 80 mole %1,4-cyclohexanedimethanol; 20 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to 80 mole %1,4-cyclohexanedimethanol; 20 to 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 50 to 80 mole %1,4-cyclohexanedimethanol; 20 to 45 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 55 to 80 mole %1,4-cyclohexanedimethanol; 20 to 40 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 60 to 80 mole %1,4-cyclohexanedimethanol; 20 to 35 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 65 to 80 mole %1,4-cyclohexanedimethanol; 20 to 30 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 70 to 80 mole %1,4-cyclohexandimethanol; and 20 to 25 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 75 to 80 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 25 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to75 mole % 1,4-cyclohexanedimethanol; 25 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 75 mole %1,4-cyclohexanedimethanol; 25 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 75 mole %1,4-cyclohexanedimethanol; 25 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 75 mole %1,4-cyclohexanedimethanol; 25 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 75 mole %1,4-cyclohexanedimethanol, 25 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 75 mole %1,4-cyclohexanedimethanol; 25 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 75 mole %1,4-cyclohexanedimethanol; 25 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 75 mole %1,4-cyclohexanedimethanol; 25 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to 75 mole %1,4-cyclohexanedimethanol; 25 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to 75 mole %1,4-cyclohexanedimethanol; 25 to 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 50 to 75 mole %1,4-cyclohexanedimethanol; 25 to 45 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 55 to 75 mole %1,4-cyclohexanedimethanol; 25 to 40 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 60 to 75 mole %1,4-cyclohexanedimethanol; 25 to 35 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 65 to 75 mole %1,4-cyclohexanedimethanol; and 25 to 30 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 70 to 75 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 30 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to70 mole % 1,4-cyclohexanedimethanol; 30 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 70 mole %1,4-cyclohexanedimethanol; 30 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 70 mole %1,4-cyclohexanedimethanol; 30 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 70 mole %1,4-cyclohexanedimethanol; 30 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 70 mole %1,4-cyclohexanedimethanol, 30 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 70 mole %1,4-cyclohexanedimethanol; 30 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 70 mole %1,4-cyclohexanedimethanol; 30 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 70 mole %1,4-cyclohexanedimethanol; 30 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to 70 mole %1,4-cyclohexanedimethanol; 30 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to 70 mole %1,4-cyclohexanedimethanol; 30 to 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 50 to 70 mole %1,4-cyclohexanedimethanol; 30 to less than 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and greater than 50 to 70 mole %1,4-cyclohexanedimethanol; 30 to 45 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 55 to 70 mole %1,4-cyclohexanedimethanol; 30 to 40 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 60 to 70 mole %1,4-cyclohexanedimethanol; 30 to 35 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 65 to 70 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 35 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to65 mole % 1,4-cyclohexanedimethanol; 35 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 65 mole %1,4-cyclohexanedimethanol; 35 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 65 mole %1,4-cyclohexanedimethanol; 35 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 65 mole %1,4-cyclohexanedimethanol; 35 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 65 mole %1,4-cyclohexanedimethanol, 35 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 65 mole %1,4-cyclohexanedimethanol; 35 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 65 mole %1,4-cyclohexanedimethanol; 35 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 65 mole %1,4-cyclohexanedimethanol; 35 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to 65 mole %1,4-cyclohexanedimethanol; 35 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to 65 mole %1,4-cyclohexanedimethanol; 35 to 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 50 to 65 mole %1,4-cyclohexanedimethanol; 35 to less than 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and greater than 50 to 65 mole %1,4-cyclohexanedimethanol; 35 to 45 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 55 to 65 mole %1,4-cyclohexanedimethanol; 35 to 40 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 60 to 65 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 37 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to63 mole % 1,4-cyclohexanedimethanol; 37 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 63 mole %1,4-cyclohexanedimethanol; 37 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 63 mole %1,4-cyclohexanedimethanol; 37 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 63 mole %1,4-cyclohexanedimethanol; 37 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 63 mole %1,4-cyclohexanedimethanol, 37 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 63 mole %1,4-cyclohexanedimethanol; 37 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 63 mole %1,4-cyclohexanedimethanol; 37 to 63 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 37 to 63 mole %1,4-cyclohexanedimethanol; 37 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to 63 mole %1,4-cyclohexanedimethanol; 37 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to 63 mole %1,4-cyclohexanedimethanol; 37 to 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 50 to 63 mole %1,4-cyclohexanedimethanol; 37 to less than 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and greater than 50 to 63 mole %1,4-cyclohexanedimethanol; 37 to 45 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 55 to 63 mole %1,4-cyclohexanedimethandl; 37 to 40 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 60 to 63 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 40 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to60 mole % 1,4-cyclohexanedimethanol; 40 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 60 mole %1,4-cyclohexanedimethanol; 40 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 60 mole %1,4-cyclohexanedimethanol; 40 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 60 mole %1,4-cyclohexanedimethanol; 40 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 60 mole %1,4-cyclohexanedimethanol, 40 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 60 mole %1,4-cyclohexanedimethanol; 40 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 60 mole %1,4-cyclohexanedimethanol; 40 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 60 mole %1,4-cyclohexanedimethanol; 40 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to 60 mole %1,4-cyclohexanedimethanol; 40 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to 60 mole %1,4-cyclohexanedimethanol; 40 to less than 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and greater than 50 to 60 mole %1,4-cyclohexanedimethanol; 40 to 50 mole %2,2,4,4-tetramethyl-i1,3-cyclobutanediol and 50 to 60 mole %1,4-cyclohexanedimethanol; and 40 to 45 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 55 to 60 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 45 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to55 mole % 1,4-cyclohexanedimethanol; 45 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 55 mole %1,4-cyclohexanedimethanol; 45 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 55 mole %1,4-cyclohexanedimethanol; 45 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 55 mole %1,4-cyclohexanedimethanol; 45 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 55 mole %1,4-cyclohexanedimethanol, 45 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 55 mole %1,4-cyclohexanedimethanol; 45 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 55 mole %1,4-cyclohexanedimethanol; 45 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 55 mole %1,4-cyclohexanedimethanol; 45 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to 55 mole %1,4-cyclohexanedimethanol; greater than 45 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to less than 55 mole %1,4-cyclohexanedimethanol; 45 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to 55 mole %1,4-cyclohexanedimethanol; and 45 to 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 50 to 55 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: greater than 50 to 99 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to less than 50 mole %1,4-cyclohexanedimethanol; greater than 50 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to less than 50 mole %1,4-cyclohexanedimethanol; greater than 50 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to less than 50 mole %1,4-cyclohexanedimethanol; greater than 50 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to less than 50 mole %1,4-cyclohexanedimethanol; greater than 50 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to less than 50 mole %1,4-cyclohexanedimethanol, greater than 50 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to less than 50 mole %1,4-cyclohexanedimethanol; greater than 50 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to less than 50 mole %1,4-cyclohexanedimethanol; greater than 50 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to less than 50 mole %1,4-cyclohexanedimethanol; greater than 50 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to less than 50 mole %1,4-cyclohexanedimethanol; and greater than 50 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to less than 50 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 50 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to50 mole % 1,4-cyclohexanedimethanol; 50 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 50 mole %1,4-cyclohexanedimethanol; 50 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 50 mole %1,4-cyclohexanedimethanol; 50 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 50 mole %1,4-cyclohexanedimethanol; 50 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 50 mole %1,4-cyclohexanedimethanol, 50 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 50 mole %1,4-cyclohexanedimethanol; 50 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 50 mole %1,4-cyclohexanedimethanol; 50 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 50 mole %1,4-cyclohexanedimethanol; 50 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to 50 mole %1,4-cyclohexanedimethanol; and 50 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to 50 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 55 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to45 mole % 1,4-cyclohexanedimethanol; 55 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 45 mole %1,4-cyclohexanedimethanol; 55 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 45 mole %1,4-cyclohexanedimethanol; 55 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 45 mole %1,4-cyclohexanedimethanol; 55 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 45 mole %1,4-cyclohexanedimethanol, 55 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 45 mole %1,4-cyclohexanedimethanol; 55 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 45 mole %1,4-cyclohexanedimethanol; 55 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 45 mole %1,4-cyclohexanedimethanol; and 55 to 60 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 40 to 45 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 60 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to40 mole % 1,4-cyclohexanedimethanol; 60 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 40 mole %1,4-cyclohexanedimethanol; 60 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 40 mole %1,4-cyclohexanedimethanol; 60 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 40 mole %1,4-cyclohexanedimethanol; 60 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 40 mole %1,4-cyclohexanedimethanol, 60 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 40 mole %1,4-cyclohexanedimethanol; and 60 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 30 to 40 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the invention include but are not limited to atleast one of the following combinations of ranges: 65 to 99 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to 35 mole %1,4-cyclohexanedimethanol; 65 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 35 mole %1,4-cyclohexanedimethanol; 65 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 35 mole %1,4-cyclohexanedimethanol; 65 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 35 mole %1,4-cyclohexanedimethanol; 65 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 35 mole %1,4-cyclohexanedimethanol, 65 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 35 mole %1,4-cyclohexanedimethanol; and 65 to 70 mole%.2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 40 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the inventioninclude.but are not limited to at least one of the followingcombinations of ranges: 70 to 99 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to 30 mole %1,4-cyclohexanedimethanol; 70 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 30 mole %1,4-cyclohexanedimethanol; 70 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 30 mole %1,4-cyclohexanedimethanol; 70 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 30 mole %1,4-cyclohexanedimethanol; 70 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 20 to 30 mole %1,4-cyclohexanedimethanol, and 70 to 75 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 25 to 30 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 75 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to25 mole % 1,4-cyclohexanedimethanol; 75 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 25 mole %1,4-cyclohexanedimethanol; 75 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 25 mole %1,4-cyclohexanedimethanol; 75 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 25 mole %1,4-cyclohexanedimethanol, and 75 to 80 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 20 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: 80 to 99 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1 to20 mole % 1,4-cyclohexanedimethanol; 80 to 95 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 5 to 20 mole %1,4-cyclohexanedimethanol; 80 to 90 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 10 to 20 mole %1,4-cyclohexanedimethanol, and 80 to 85 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 15 to 20 mole %1,4-cyclohexanedimethanol.

In other aspects of the invention, the glycol component for thepolyesters useful in the ophthalmic product(s) of the invention includebut are not limited to at least one of the following combinations ofranges: greater than 45 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to less than 55 mole %1,4-cyclohexanedimethanol; greater than 45 to 50 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 50 to less than 55 mole %1,4-cyclohexanedimethanol; 46 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 45 to 54 mole %1,4-cyclohexanedimethanol; and 46 to 65 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol and 35 to 54 mole %1,4-cyclohexanedimethanol.

In addition to the diols set forth above, the polyesters useful in thepolyester compositions of the ophthalmic product(s) of the invention mayalso be made from 1,3-propanediol, 1,4-butanediol, or mixtures thereof.It is contemplated that compositions of the invention made from1,3-propanediol, 1,4-butanediol, or mixtures thereof can possess atleast one of the Tg ranges described herein, at least one of theinherent viscosity ranges described herein, and/or at least one of theglycol or diacid ranges described herein. In addition or in thealternative, the polyesters made from 1,3-propanediol or 1,4-butanediolor mixtures thereof may also be made from 1,4-cyclohexanedmethanol in atleast one of the following amounts: from 0.1 to 99 mole %; from 0.1 to90 mole %; from 0.1 to 80 mole %; from 0.1 to 70 mole %; from 0.1 to 60mole %; from 0.1 to 50 mole %; from 0.1 to 40 mole %; from 0.1 to 35mole %; from 0.1 to 30 mole %; from 0.1 to 25 mole %; from 0.1 to 20mole %; from 0.1 to 15 mole %; from 0.1 to 10 mole %; from 0.1 to 5 mole%; from 1 to 99 mole %; from 1 to 90 mole %, from 1 to 80 mole %; from 1to 70 mole %; from 1 to 60 mole %; from 1 to 50 mole %; from 1 to 40mole %; from 1 to 35 mole %; from 1 to 30 mole %; from 1 to 25 mole %;from 1 to 20 mole %; from 1 to 15 mole %; from 1 to 10 mole %; from 1 to5 mole %; from 5 to 99 mole %, from 5 to 90 mole %, from 5 to 80 mole %;5 to 70 mole %; from 5 to 60 mole %; from 5 to 50 mole %; from 5 to 40mole %; from 5 to 35 mole %; from 5 to 30 mole %; from 5 to 25 mole %;from 5 to 20 mole %; and from 5 to 15 mole %; from 5 to 10 mole %; from10 to 99 mole %; from 10 to 90 mole %; from 10 to 80 mole %; from 10 to70 mole %; from 10 to 60 mole %; from 10 to 50 mole %; from 10 to 40mole %; from 10 to 35 mole %; from 10 to 30 mole %; from 10 to 25 mole%; from 10 to 20 mole %; from 10 to 15 mole %; from 20 to 99 mole %;from 20 to 90 mole %; from 20 to 80 mole %; from 20 to 70 mole %; from20 to 60 mole %; from 20 to 50 mole %; from 20 to 40 mole %; from 20 to35 mole %; from 20 to 30 mole %; and from 20 to 25 mole

For certain embodiments of the invention, the polyesters useful in theinvention may exhibit at least one of the following inherent viscositiesas determined in 60/40 (wt/wt) phenol/tetrachloroethane at aconcentration of 0.5 g/100 ml at 25° C.: 0.10 to 1.2 dL/g; 0.10 to 1.1dL/g; 0.10 to 1 dL/g; 0.10 to less than 1 dL/g; 0.10 to 0.98 dL/g; 0.10to 0.95 dL/g; 0.10 to 0.90 dL/g; 0.10 to 0.85 dL/g; 0.10 to 0.80 dL/g;0.10 to 0.75 dL/g; 0.10 to less than 0.75 dL/g; 0.10 to 0.72 dL/g; 0.10to 0.70 dL/g; 0.10 to less than 0.70 dL/g; 0.10 to 0.68 dL/g; 0.10 toless than 0.68 dL/g; 0.10 to 0.65 dL/g; 0.20 to 1.2 dL/g; 0.20 to 1.1dL/g; 0.20 to 1 dL/g; 0.20 to less than 1 dL/g; 0.20 to 0.98 dL/g; 0.20to 0.95 dL/g; 0.20 to 0.90 dL/g; 0.20 to 0.85 dL/g; 0.20 to 0.80 dL/g;0.20 to 0.75 dL/g; 0.20 to less than 0.75 dL/g; 0.20 to 0.72 dL/g; 0.20to 0.70 dL/g; 0.20 to less than 0.70 dL/g; 0.20 to 0.68 dL/g; 0.20 toless than 0.68 dL/g; 0.20 to 0.65 dL/g; 0.35 to 1.2 dL/g; 0.35 to 1.1dL/g; 0.35 to 1 dL/g; 0.35 to less than 1 dL/g; 0.35 to 0.98 dL/g; 0.35to 0.95 dL/g; 0.35 to 0.90 dL/g; 0.35 to 0.85 dL/g; 0.35 to 0.80 dL/g;0.35 to 0.75 dL/g; 0.35 to less than 0.75 dL/g; 0.35 to 0.72 dL/g; 0.35to 0.70 dL/g; 0.35 to less than 0.70 dL/g; 0.35 to 0.68 dL/g; 0.35 toless than 0.68 dL/g; 0.35 to 0.65 dL/g; 0.40 to 1.2 dL/g; 0.40 to 1.1dL/g; 0.40 to 1 dL/g; 0.40 to less than 1 dL/g; 0.40 to 0.98 dL/g; 0.40to 0.95 dL/g; 0.40 to 0.90 dL/g; 0.40 to 0.85 dL/g; 0.40 to 0.80 dL/g;0.40 to 0.75 dL/g; 0.40 to less than 0.75 dL/g; 0.40 to 0.72 dL/g; 0.40to 0.70 dL/g; 0.40 to less than 0.70 dL/g; 0.40 to 0.68 dL/g; 0.40 toless than 0.68 dL/g; 0.40 to 0.65 dL/g; greater than 0.42 to 1.2 dL/g;greater than 0.42 to 1.1 dL/g; greater than 0.42 to 1 dL/g; greater than0.42 to less than 1 dL/g; greater than 0.42 to 0.98 dL/g; greater than0.42 to 0.95 dL/g; greater than 0.42 to 0.90 dL/g; greater than 0.42 to0.85 dL/g; greater than 0.42 to 0.80 dL/g; greater than 0.42 to 0.75dL/g; greater than 0.42 to less than 0.75 dL/g; greater than 0.42 to0.72 dL/g; greater than 0.42 to less than 0.70 dL/g; greater than 0.42to 0.68 dL/g; greater than 0.42 to less than 0.68 dL/g; and greater than0.42 to 0.65 dL/g.

For certain embodiments of the invention, the polyesters useful in theinvention may exhibit at least one of the following inherent viscositiesas determined in 60/40 (wt/wt) phenol/tetrachloroethane at aconcentration of 0.5 g/100 ml at 25° C: 0.45 to 1.2 dL/g; 0.45 to 1.1dL/g; 0.45 to 1 dL/g; 0.45 to 0.98 dL/g; 0.45 to 0.95 dL/g; 0.45 to 0.90dL/g; 0.45 to 0.85 dL/g; 0.45 to 0.80 dL/g; 0.45 to 0.75 dL/g; 0.45 toless than 0.75 dL/g; 0.45 to 0.72 dL/g; 0.45 to 0.70 dL/g; 0.45 to lessthan 0.70 dL/g; 0.45 to 0.68 dL/g; 0.45 to less than 0.68 dL/g; 0.45 to0.65 dL/g; 0.50 to 1.2 dL/g; 0.50 to 1.1 dL/g; 0.50 to 1 dL/g; 0.50 toless than 1 dL/g; 0.50 to 0.98 dL/g; 0.50 to 0.95 dL/g; 0.50 to 0.90dL/g; 0.50 to 0.85 dL/g; 0.50 to 0.80 dL/g; 0.50 to 0.75 dL/g; 0.50 toless than 0.75 dL/g; 0.50 to 0.72 dL/g; 0.50 to 0.70 dL/g; 0.50 to lessthan 0.70 dL/g; 0.50 to 0.68 dL/g; 0.50 to less than 0.68 dL/g; 0.50 to0.65 dL/g; 0.55 to 1.2 dL/g; 0.55 to 1.1 dL/g; 0.55 to 1 dL/g; 0.55 toless than 1 dL/g; 0.55 to 0.98 dL/g; 0.55 to 0.95 dL/g; 0.55 to 0.90dL/g; 0.55 to 0.85 dL/g; 0.55 to 0.80 dL/g; 0.55 to 0.75 dL/g; 0.55 toless than 0.75 dL/g; 0.55 to 0.72 dL/g; 0.55 to 0.70 dL/g; 0.55 to lessthan 0.70 dL/g; 0.55 to 0.68 dL/g; 0.55 to less than 0.68 dL/g; 0.55 to0.65 dL/g; 0.58 to 1.2 dL/g; 0.58 to 1.1 dL/g; 0.58 to 1 dL/g; 0.58 toless than 1 dL/g; 0.58 to 0.98 dL/g; 0.58 to 0.95 dL/g; 0.58 to 0.90dL/g; 0.58 to 0.85 dL/g; 0.58 to 0.80 dL/g; 0.58 to 0.75 dL/g; 0.58 toless than 0.75 dL/g; 0.58 to 0.72 dL/g; 0.58 to 0.70 dL/g; 0.58 to lessthan 0.70 dL/g; 0.58 to 0.68 dL/g; 0.58 to less than 0.68 dL/g; 0.58 to0.65 dL/g; 0.60 to 1.2 dL/g; 0.60 to 1.1 dL/g; 0.60 to 1 dL/g; 0.60 toless than 1 dL/g; 0.60 to 0.98 dL/g; 0.60 to 0.95 dL/g; 0.60 to 0.90dL/g; 0.60 to 0.85 dL/g; 0.60 to 0.80 dL/g; 0.60 to 0.75 dL/g; 0.60 toless than 0.75 dL/g; 0.60 to 0.72 dL/g; 0.60 to 0.70 dL/g; 0.60 to lessthan 0.70 dL/g; 0.60 to 0.68 dL/g; 0.60 to less than 0.68 dL/g; 0.60 to0.65 dL/g; 0.65 to 1.2 dL/g; 0.65 to 1.1 dL/g; 0.65 to 1 dL/g; 0.65 toless than 1 dL/g; 0.65 to 0.98 dL/g; 0.65 to 0.95 dL/g; 0.65 to 0.90dL/g; 0.65 to 0.85 dL/g; 0.65 to 0.80 dL/g; 0.65 to 0.75 dL/g; 0.65 toless than 0.75 dL/g; 0.65 to 0.72 dL/g; 0.65 to 0.70 dL/g; 0.65 to lessthan 0.70 dL/g; 0.68 to 1.2 dL/g; 0.68 to 1.1 dL/g; 0.68 to 1 dL/g; 0.68to less than 1 dL/g; 0.68 to 0.98 dL/g; 0.68 to 0.95 dL/g; 0.68 to 0.90dL/g; 0.68 to 0.85 dL/g; 0.68 to 0.80 dL/g; 0.68 to 0.75 dL/g; 0.68 toless than 0.75 dL/g; 0.68 to 0.72 dL/g; greater than 0.76 dug to 1.2dL/g; greater than 0.76 dL/g to 1.1 dL/g; greater than 0.76 dL/g to 1dL/g; greater than 0.76 dL/g to less than 1 dL/g; greater than 0.76 dL/gto 0.98dL/g; greater than 0.76 dL/g to 0.95 dL/g; greater than 0.76 dL/gto 0.90 dL/g; greater than 0.80 dL/g to 1.2 dL/g; greater than 0.80 dL/gto 1.1 dL/g; greater than 0.80 dL/g to 1 dL/g; greater than 0.80 dL/g toless than 1 dL/g; greater than 0.80 dL/g to 1.2 dL/g; greater than 0.80dL/g to 0.98dL/g; greater than 0.80 dL/g to 0.95 dL/g; greater than 0.80dL/g to 0.90 dL/g.

It is contemplated that compositions useful in the ophthalmic product(s)of the invention can possess at least one of the inherent viscosityranges described herein and at least one of the monomer ranges for thecompositions described herein unless otherwise stated. It is alsocontemplated that compositions useful in the ophthalmic product(s) ofthe invention can posses at least one of the Tg ranges described hereinand at least one of the monomer ranges for the compositions describedherein unless otherwise stated. It is also contemplated thatcompositions useful in the ophthalmic product(s) of the invention canposses at least one of the Tg ranges described herein, at least one ofthe inherent viscosity ranges described herein, and at least one of themonomer ranges for the compositions described herein unless otherwisestated.

For the desired polyester, the molar ratio of cis/trans2,2,4,4-tetramethyl-1,3-cyclobutanediol can vary from the pure form ofeach or mixtures thereof. In certain embodiments, the molar percentagesfor cis and/or trans 2,2,4,4,-tetramethyl-1,3-cyclobutanediol aregreater than 50 mole % cis and less than 50 mole % trans; or greaterthan 55 mole % cis and less than 45 mole % trans; or 30 to 70 mole % cisand 70 to 30% trans; or 40 to 60 mole % cis and 60 to 40 mole % trans;or 50 to 70 mole % trans and 50 to 30% cis or 50 to 70 mole % cis and 50to 30% trans; or 60 to 70 mole % cis and 30 to 40 mole % trans; orgreater than 70 mole cis and less than 30 mole % trans; wherein thetotal sum of the mole percentages for cis- andtrans-2,2,4,4-tetramethyl-1,3-cyclobutanediol is equal to 100 mole %.The molar ratio of cis/trans 1,4-cyclohexandimethanol can vary withinthe range of 50/50 to 0/100, such as between 40/60 to 20/80.

In certain embodiments, terephthalic acid or an ester thereof, such as,for example, dimethyl terephthalate, or a mixture of terephthalic acidand an ester thereof, makes up most or all of the dicarboxylic acidcomponent used to form the polyesters useful in the invention. Incertain embodiments, terephthalic acid residues can make up a portion orall of the dicarboxylic acid component used to form the presentpolyester at a concentration of at least 70 mole %, such as at least 80mole %, at least 90 mole %, at least 95 mole %, at least 99 mole %, or100 mole %. In certain embodiments, higher amounts of terephthalic acidcan be used in order to produce a higher impact strength polyester. Inone embodiment, dimethyl terephthalate is part or all of thedicarboxylic acid component used to make the polyesters useful in thepresent invention. For the purposes of this disclosure, the terms“terephthalic acid” and “dimethyl terephthalate” are usedinterchangeably herein. In all embodiments, ranges of from 70 to 100mole %; or 80 to 100 mole %; or 90 to 100 mole %; or 99 to 100 mole %;or 100 mole % terephthalic acid and/or dimethyl terephthalate and/ormixtures thereof may be used.

In addition to terephthalic acid, the dicarboxylic acid component of thepolyester useful in the invention can comprise up to 30 mole %, up to 20mole %, up to 10 mole %, up to 5 mole %, or up to 1 mole % of one ormore modifying aromatic dicarboxylic acids. Yet another embodimentcontains 0 mole % modifying aromatic dicarboxylic acids. Thus, ifpresent, it is contemplated that the amount of one or more modifyingaromatic dicarboxylic acids can range from any of these precedingendpoint values including, for example, from 0.01 to 30 mole %, 0.01 to20 mole %, from 0.01 to 10 mole %, from 0.01 to 5 mole % and from 0.01to 1 mole. In one embodiment, modifying aromatic dicarboxylic acids thatmay be used in the present invention include but are not limited tothose having up to 20 carbon atoms, and which can be linear,para-oriented, or symmetrical. Examples of modifying aromaticdicarboxylic acids which may be used in this invention include, but arenot limited to, isophthalic acid, 4,4′-biphenyldicarboxylic acid, 1,4-,1,5-, 2,6-, 2,7-naphthalenedicarboxylic acid, andtrans-4,4′-stilbenedicarboxylic acid, and esters thereof. In oneembodiment, the modifying aromatic dicarboxylic acid is isophthalicacid.

The carboxylic acid component of the polyesters useful in the inventioncan be further modified with up to 10 mole %, such as up to 5 mole % orup to 1 mole % of one or more aliphatic dicarboxylic acids containing2-16 carbon atoms, such as, for example, malonic, succinic, glutaric,adipic, pimelic, suberic, azelaic and dodecanedioic dicarboxylic acids.Certain embodiments can also comprise 0.01 or more mole %, such as 0.1or more mole %, 1 or more mole %, 5 or more mole %, or 10 or more mole %of one or more modifying aliphatic dicarboxylic acids. Yet anotherembodiment contains 0 mole % modifying aliphatic dicarboxylic acids.Thus, if present, it is contemplated that the amount of one or moremodifying aliphatic dicarboxylic acids can range from any of thesepreceding endpoint values including, for example, from 0.01 to 10 mole %and from 0.1 to 10 mole %. The total mole % of the dicarboxylic acidcomponent is 100 mole %.

Esters of terephthalic acid and the other modifying dicarboxylic acidsor their corresponding esters and/or salts may be used instead of thedicarboxylic acids. Suitable examples of dicarboxylic acid estersinclude, but are not limited to, the dimethyl, diethyl, dipropyl,diisopropyl, dibutyl, and diphenyl esters. In one embodiment, the estersare chosen from at least one of the following: methyl, ethyl, propyl,isopropyl, and phenyl esters.

The 1,4-cyclohexanedimethanol may be cis, trans, or a mixture thereof,for example a cis/trans ratio of 60:40 to 40:60. In another embodiment,the trans-1,4-cyclohexanedimethanol can be present in an amount of 60 to80 mole %.

The glycol component of the polyester portion of the polyestercomposition useful in the invention can contain 25 mole % or less of oneor more modifying glycols which are not2,2,4,4-tetramethyl-1,3-cyclobutanediol or 1,4-cyclohexanedimethanol; inone embodiment, the polyesters useful in the invention may contain lessthan 15 mole % of one or more modifying glycols. In another embodiment,the polyesters useful in the invention can contain 10 mole % or less ofone or more modifying glycols. In another embodiment, the polyestersuseful in the invention can contain 5 mole % or less of one or moremodifying glycols. In another embodiment, the polyesters useful in theinvention can contain 3 mole % or less of one or more modifying glycols.In another embodiment, the polyesters useful in the invention cancontain 0 mole % modifying glycols. Certain embodiments can also contain0.01 or more mole %, such as 0.1 or more mole %, 1 or more mole %, 5 ormore mole %, or 10 or more mole % of one or more modifying glycols.Thus, if present, it is contemplated that the amount of one or moremodifying glycols can range from any of these preceding endpoint valuesincluding, for example, from 0.01 to 15 mole % and from 0.1 to 10 mole%.

Modifying glycols useful in the polyesters useful in the invention referto diols other than 2,2,4,4,-tetramethyl-1,3-cyclobutanediol and1,4-cyclohexanedimethanol and may contain 2 to 16 carbon atoms. Examplesof suitable modifying glycols include, but are not limited to, ethyleneglycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, p-xylene glycol ormixtures thereof. In one embodiment, the modifying glycol is ethyleneglycol. In another embodiment, the modifying glycols are 1,3-propanedioland/or 1,4-butanediol. In another embodiment, ethylene glycol isexcluded as a modifying diol. In another embodiment, 1,3-propanediol and1,4-butanediol are excluded as modifying diols. In another embodiment,2,2-dimethyl-1,3-propanediol is excluded as a modifying diol.

The polyesters and/or the polycarbonates useful in the polyesterscompositions of the invention can comprise from 0 to 10 mole percent,for example, from 0.01 to 5 mole percent, from 0.01 to 1 mole percent,from 0.05 to 5 mole percent, from 0.05 to 1 mole percent, or from 0.1 to0.7 mole percent, based the total mole percentages of either the diol ordiacid residues; respectively, of one or more residues of a branchingmonomer, also referred to herein as a branching agent, having 3 or morecarboxyl substituents, hydroxyl substituents, or a combination thereof.In certain embodiments, the branching monomer or agent may be addedprior to and/or during and/or after the polymerization of the polyester.The polyester(s) useful in the invention can thus be linear or branched.The polycarbonate can also be linear or branched. In certainembodiments, the branching monomer or agent may be added prior to and/orduring and/or after the polymerization of the polycarbonate.

Examples of branching monomers include, but are notlimited to,multifunctional acids or multifunctional alcohols such as trimelliticacid, trimellitic anhydride, pyromellitic dianhydride,trimethylolpropane, glycerol, pentaerythritol, citric acid, tartaricacid, 3-hydroxyglutaric acid and the like. In one embodiment, thebranching monomer residues can comprise 0.1 to 0.7 mole percent of oneor more residues chosen from at least one of the following: trimelliticanhydride, pyromellitic dianhydride, glycerol, sorbitol,1,2,6-hexanetriol, pentaerythritol, trimethylolethane, and/or trimesicacid. The branching monomer may be added to the polyester reactionmixture or blended with the polyester in the form of a concentrate asdescribed, for example, in U.S. Pat. Nos. 5,654,347 and 5,696,176, whosedisclosure regarding branching monomers is incorporated herein byreference.

The glass transition temperature (Tg) of the polyesters useful in theinvention was determined using a TA DSC 2920 from Thermal AnalystInstrument at a scan rate of 20° C./min.

Because of the long crystallization half-times (e.g., greater than 5minutes) at 170° C. exhibited by certain polyesters useful in thepresent invention, it is possible to produce injection molded ophthalmicproducts, compression molded ophthalmic products, and solution castedophthalmic products. The polyesters of the invention can be amorphous orsemicrystalline. In one aspect, certain polyesters useful in theinvention can have relatively low crystallinity. Certain polyestersuseful in the invention can thus have a substantially amorphousmorphology, meaning that the polyesters comprise substantially unorderedregions of polymer.

In one embodiment, an “amorphous” polyester can have a crystallizationhalf-time of greater than 5 minutes at 170° C. or greater than 10minutes at 170° C. or greater than 50 minutes at 170° C. or greater than100 minutes at 170° C. In one embodiment, of the invention, thecrystallization half-times are greater than 1,000 minutes at 170° C. Inanother embodiment of the invention, the crystallization half-times ofthe polyesters useful in the invention are greater than 10,000 minutesat 170° C. The crystallization half time of the polyester, as usedherein, may be measured using methods well-known to persons of skill inthe art. For example, the crystallization half time of the polyester,t_(1/2), can be determined by measuring the light transmission of asample via a laser and photo detector as a function of time on atemperature controlled hot stage. This measurement can be done byexposing the polymers to a temperature, T_(max), and then cooling it tothe desired temperature. The sample can then be held at the desiredtemperature by a hot stage while transmission measurements are made as afunction of time. Initially, the sample can be visually clear with highlight transmission and becomes opaque as the sample crystallizes. Thecrystallization half-time is the time at which the light transmission ishalfway between the initial transmission and the final transmission.T_(max) is defined as the temperature required to melt the crystallinedomains of the sample (if crystalline domains are present). The samplecan be heated to Tmax to condition the sample prior to crystallizationhalf time measurement. The absolute Tmax temperature is different foreach composition. For example PCT can be heated to some temperaturegreater than 290° C. to melt the crystalline domains.

As shown in Table 1 and FIG. 1 of the Examples,2,2,4,4-tetramethyl-1,3-cyclobutanediol is more effective than othercomonomers such ethylene glycol and isophthalic acid at increasing thecrystallization half-time, i.e., the time required for a polymer toreach half of its maximum crystallinity. By decreasing thecrystallization rate of PCT, i.e. increasing the crystallizationhalf-time, amorphous articles based on modified PCT may be fabricated bymethods known in the art such as extrusion, injection molding, and thelike. As shown in Table 1, these materials can exhibit higher glasstransition temperatures and lower densities than other modified PCTcopolyesters.

The polyesters can exhibit an improvement in toughness combined withprocessability for some of the embodiments of the invention. Forexample, it is unexpected that lowering the inherent viscosity slightlyof the polyesters useful in the invention results in a more processablemelt viscosity while retaining good physical properties of thepolyesters such as toughness and heat resistance.

Increasing the content of 1,4-cyclohexanedimethanol in a copolyesterbased on terephthalic acid, ethylene glycol, and1,4-cyclohexanedimethanol can improve toughness, which can be determinedby the brittle-to-ductile transition temperature in a notched Izodimpact strength test as measured by ASTM D256. This toughnessimprovement, by lowering of the brittle-to-ductile transitiontemperature with 1,4-cyclohexanedimethanol, is believed to occur due tothe flexibility and conformational behavior of 1,4-cyclohexanedimethanolin the copolyester. Incorporating2,2,4,4-tetramethyl-1,3-cyclobutanediol into PCT is believed to improvetoughness, by lowering the brittle-to-ductile transition temperature, asshown in Table 2 and FIG. 2 of the Examples. This is unexpected giventhe rigidity of 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

In one embodiment, the melt viscosity of the polyester(s) useful in theinvention is less than 30,000 poise as measured a 1 radian/second on arotary melt rheometer at 290° C. In another embodiment, the meltviscosity of the polyester(s) useful in the invention is less than20,000 poise as measured a 1 radian/second on a rotary melt rheometer at290° C.

In one embodiment, the melt viscosity of the polyester(s) useful in theinvention is less than 15,000 poise as measured at 1 radian/second(rad/sec) on a rotary melt rheometer at 290° C. In one embodiment, themelt viscosity of the polyester(s) useful in the invention is less than10,000 poise as measured at 1 radian/second (rad/sec) on a rotary meltrheometer at 290° C. In another embodiment, the melt viscosity of thepolyester(s) useful in the invention is less than 6,000 poise asmeasured at 1 radian/second on a rotary melt rheometer at 290° C.Viscosity at rad/sec is related to processability. Typical polymers haveviscosities of less than 10,000 poise as measured at 1 radian/secondwhen measured at their processing temperature. Polyesters are typicallynot processed above 290° C. Polycarbonate is typically processed at 290°C. The viscosity at 1 rad/sec of a typical 12 melt flow ratepolycarbonate is 7000 poise at 290° C.

In one embodiment, certain polyesters useful in this invention arevisually clear. The term “visually clear” is defined herein as anappreciable absence of cloudiness, haziness, and/or muddiness, wheninspected visually. When the polyesters are blended with polycarbonate,including bisphenol A polycarbonates, the blends can be visually clearin one aspect of the invention.

The present polyesters possess one or more of the following properties.In other embodiments, the polyesters useful in the invention may have ayellowness index (ASTM D-1925) of less than 50, such as less than 20.

In one embodiment, polyesters of this invention exhibit superior notchedtoughness in thick sections. Notched Izod impact strength, as describedin ASTM D256, is a common method of measuring toughness. When tested bythe Izod method, polymers can exhibit either a complete break failuremode, where the test specimen breaks into two distinct parts, or apartial or no break failure mode, where the test specimen remains as onepart. The complete break failure mode is associated with low energyfailure. The partial and no break failure modes are associated with highenergy failure. A typical thickness used to measure Izod toughness is⅛″. At this thickness, very few polymers are believed to exhibit apartial or no break failure mode, polycarbonate being one notableexample. When the thickness of the test specimen is increased to ¼″,however, no commercial amorphous materials exhibit a partial or no breakfailure mode. In one embodiment, compositions of the present exampleexhibit a no break failure mode when tested in Izod using a ¼″ thickspecimen.

The polyesters useful in the invention can possess one or more of thefollowing properties. In one embodiment, the polyesters useful in theinvention exhibit a notched Izod impact strength of at least 150 J/m (3ft-lb/in) at 23° C. with a 10-mil notch in a 3.2 mm (⅛-inch) thick bardetermined according to ASTM D256; in one embodiment, the polyestersuseful in the invention exhibit a notched Izod impact strength of atleast (400 J/m) 7.5 ft-lb/in at 23° C. with a 10-mil notch in a 3.2 mm(⅛-inch) thick bar determined according to ASTM D256; in one embodiment,the polyesters useful in the invention exhibit a notched Izod impactstrength of at least 1000 J/m (18 ft-lb/in) at 23° C. with a 10-milnotch in a 3.2 mm (⅛-inch) thick bar determined according to ASTM D256.In one embodiment, the polyesters useful in the invention exhibit anotched Izod impact strength of at least 150 J/m (3 ft-lb/in) at 23° C.with a 10-mil notch in a 6.4 mm (¼-inch) thick bar determined accordingto ASTM D256; in one embodiment, the polyesters useful in the inventionexhibit a notched Izod impact strength of at least (400 J/m) 7.5ft-lb/in at 23° C. with a 10-mil notch in a 6.4 mm (¼-inch) thick bardetermined according to ASTM D256; in one embodiment, the polyestersuseful in the invention exhibit a notched Izod impact strength of atleast 1000 J/m (18 ft-lb/in) at 23° C. with a 10-mil notch in a 6.4 mm(¼-inch) thick bar determined according to ASTM D256.

In another embodiment, certain polyesters useful in the invention canexhibit an increase in notched Izod impact strength when measured at 0°C. of at least 3% or at least 5% or at least 10% or at least 15% ascompared to the notched Izod impact strength when measured at −5° C.with a 10-mil notch in a ⅛-inch thick bar determined according to ASTMD256. In addition, certain other polyesters can also exhibit a retentionof notched Izod impact strength within plus or minus 5% when measured at0° C. through 30° C. with a 10-mil notch in a ⅛-inch thick bardetermined according to ASTM D256.

In yet another embodiment, certain polyesters useful in the inventioncan exhibit a retention in notched Izod impact strength with a loss ofno more than 70% when measured at 23° C. with a 10-mil notch in a ¼-inchthick bar determined according to ASTM D256 as compared to notched Izodimpact strength for the same polyester when measured at the sametemperature with a 10-mil notch in a ⅛-inch thick bar determinedaccording to ASTM D256.

In one embodiment, the polyesters useful in the invention and/or thepolyester compositions of the invention, with or without toners, canhave color values L*, a* and b*, which can be determined using a HunterLab Ultrascan Spectra Colorimeter manufactured by Hunter Associates LabInc., Reston, Va. The color determinations are averages of valuesmeasured on either pellets of the polyesters or plaques or other itemsinjection molded or extruded from them They are determined by the L*a*b*color system of the CIE (International Commission on Illumination)(translated), wherein L* represents the lightness coordinate, a*represents the red/green coordinate, and b* represents the yellow/bluecoordinate. In certain embodiments, the b* values for the polyestersuseful in the invention can be from −10 to less than 10 and the L*values can be from 50 to 90. In other embodiments, the b* values for thepolyesters useful in the invention can be present in one of thefollowing ranges: −10 to 9; −10 to 8; −10 to 7; −10 to 6; −10 to 5; −10to 4; −10 to 3; −10 to 2; from −5 to 9; −5 to 8; −5 to 7; −5 to 6; −5 to5; −5 to 4; −5 to 3; −5 to 2; 0 to 9; 0 to 8; 0 to 7; 0 to 6; 0 to 5; 0to 4; 0 to 3; 0 to 2; 1 to 10; 1 to 9; 1 to 8; 1 to 7; 1 to 6; 1 to 5; 1to 4; 1 to 3; and 1 to 2. In other embodiments, the L* value for thepolyesters useful in the invention can be present in one of thefollowing ranges: 50 to 60; 50 to 70; 50 to 80; 50 to 90; 60 to 70; 60to 80; 60 to 90; 70 to 80; 79 to 90.

In one embodiment, the polyesters useful in the invention exhibit aductile-to-brittle transition temperature of less than 0° C. based on a10-mil notch in a ⅛-inch thick bar as defined by ASTM D256.

In one embodiment, the polyesters useful in the invention can exhibit atleast one of the following densities: a density of less than 1.3 g/ml at23° C.; a density of less than 1.2 g/ml at 23° C.; a density of lessthan 1.18 g/ml at 23° C.; a density of 0.80 to 1.3 g/ml at 23° C.; adensity of 0.80 to 1.2 g/ml at 23° C.; a density of 0.80 to less than1.2 g/ml at 23° C.; a density of 1.0 to 1.3 g/ml at 23° C.; a density of1.0 to 1.2 g/ml at 23° C.; a density of 1.0 to 1.1 g/ml at 23° C.; adensity of 1.13 to 1.3 g/ml at 23° C.; a density of 1.13 to 1.2 g/ml at23° C.

In some embodiments, use of the polyester compositions useful in theinvention minimizes and/or eliminates the drying step prior to meltprocessing and/or thermoforming.

The polyester portion of the polyester compositions useful in theinvention can be made by processes known from the literature such as,for example, by processes in homogenous solution, by transesterificationprocesses in the melt, and by two phase interfacial processes. Suitablemethods include, but are not limited to, the steps of reacting one ormore dicarboxylic acids with one or more glycols at a temperature of100° C. to 315° C. at a pressure of 0.1 to 760 mm Hg for a timesufficient to form a polyester. See U.S. Pat. No. 3,772,405 for methodsof producing polyesters, the disclosure regarding such methods is herebyincorporated herein by reference.

In another aspect, the invention relates to ophthalmic product(s)comprising a polyester produced by a process comprising:

(I) heating a mixture comprising the monomers useful in any of thepolyesters in the invention in the presence of a catalyst at atemperature of 150 to 240° C. for a time sufficient to produce aninitial polyester;

(II) heating the initial polyester of step (I) at a temperature of 240to 320° C. for 1 to 4 hours; and

(III) removing any unreacted glycols.

Suitable catalysts for use in this process include, but are not limitedto, organo-zinc or tin compounds. The use of this type of catalyst iswell known in the art. Examples of catalysts useful in the presentinvention include, but are not limited to, zinc acetate, butyltintris-2-ethylhexanoate, dibutyltin diacetate, and dibutyltin oxide. Othercatalysts may include, but are not limited to, those based on titanium,zinc, manganese, lithium, germanium, and cobalt. Catalyst amounts canrange from 10 ppm to 20,000 ppm or 10 to 10,000 ppm, or 10 to 5000 ppmor 10 to 1000 ppm or 10 to 500 ppm, or 10 to 300 ppm or 10 to 250 basedon the catalyst metal and based on the weight of the final polymer. Theprocess can be carried out in either a batch or continuous process.

Typically, step (I) can be carried out until 50% by weight or more ofthe 2,2,4,4-tetramethyl-1,3-cyclobutanediol has been reacted. Step (I)may be carried out under pressure, ranging from atmospheric pressure to100 psig. The term “reaction product” as used in connection with any ofthe catalysts useful in the invention refers to any product of apolycondensation or esterification reaction with the catalyst and any ofthe monomers used in making the polyester as well as the product of apolycondensation or esterification reaction between the catalyst and anyother type of additive.

Typically, Step (II) and Step (III) can be conducted at the same time.These steps can be carried out by methods known in the art such as byplacing the reaction mixture under a pressure ranging from 0.002 psig tobelow atmospheric pressure, or by blowing hot nitrogen gas over themixture.

The invention further relates to a polyester product made by the processdescribed above.

The invention further relates to a polymer blend. The blend comprises:

(a) 5 to 95 wt % of at least one of the polyesters described above; and

(b) 5 to 95 wt % of at least one polymeric component.

Suitable examples of polymeric components include, but are not limitedto, nylon, polyesters different from those described herein, polyamidessuch as ZYTEL® from DuPont; polystyrene, polystyrene copolymers, styreneacrylonitrile copolymers, acrylonitrile butadiene styrene copolymers,poly(methylmethacrylate), acrylic copolymers, poly(ether-imides) such asULTEM® (a poly(ether-imide) from General Electric); polyphenylene oxidessuch as poly(2,6-dimethylphenylene oxide) or poly(phenyleneoxide)/polystyrene blends such as NORYL 1000® (a blend ofpoly(2,6-dimethylphenylene oxide) and polystyrene resins from GeneralElectric); polyphenylene sulfides; polyphenylene sulfide/sulfones;poly(ester-carbonates); polycarbonates such as LEXAN® (a polycarbonatefrom General Electric); polysulfones; polysulfone ethers; andpoly(ether-ketones) of aromatic dihydroxy compounds; or mixtures of anyof the other foregoing polymers. The blends can be prepared byconventional processing techniques known in the art, such as meltblending or solution blending. In one embodiment, the polycarbonate isnot present in the polyester composition. If polycarbonate is used in ablend in the polyester compositions useful in the invention, the blendscan be visually clear. However, the polyester compositions useful in theinvention also contemplate the exclusion of polycarbonate as well as theinclusion of polycarbonate.

Polycarbonates useful in the invention may be prepared according toknown procedures, for example, by reacting the dihydroxyaromaticcompound with a carbonate precursor such as phosgene, a haloformate or acarbonate ester, a molecular weight regulator, an acid acceptor and acatalyst. Methods for preparing polycarbonates are known in the art andare described, for example, in U.S. Pat. No. 4,452,933, where thedisclosure regarding the preparation of polycarbonates is herebyincorporated by reference herein.

Examples of suitable carbonate precursors include, but are not limitedto, carbonyl bromide, carbonyl chloride, or mixtures thereof; diphenylcarbonate; a di(halophenyl)carbonate, e.g.,di(trichlorophenyl)carbonate, di(tribromophenyl)carbonate, and the like;di(alkylphenyl)carbonate, e.g., di(tolyl)carbonate;di(naphthyl)carbonate; di(chloronaphthyl)carbonate, or mixtures thereof;and bis-haloformates of dihydric phenols.

Examples of suitable molecular weight regulators include, but are notlimited to, phenol, cyclohexanol, methanol, alkylated phenols, such asoctylphenol, para-tertiary-butyl-phenol, and the like. In oneembodiment, the molecular weight regulator is phenol or an alkylatedphenol.

The acid acceptor may be either an organic or an inorganic acidacceptor. A suitable organic acid acceptor can be a tertiary amine andincludes, but is not limited to, such materials as pyridine,triethylamine, dimethylaniline, tributylamine, and the like. Theinorganic acid acceptor can be either a hydroxide, a carbonate, abicarbonate, or a phosphate of an alkali or alkaline earth metal.

The catalysts that can be used include, but are not limited to, thosethat typically aid the polymerization of the monomer with phosgene.Suitable catalysts include, but are not limited to, tertiary amines suchas triethylamine, tripropylamine, N,N-dimethylaniline, quaternaryammonium compounds such as, for example, tetraethylammonium bromide,cetyl triethyl ammonium bromide, tetra-n-heptylammonium iodide,tetra-n-propyl ammonium bromide, tetramethyl ammonium chloride,tetra-methyl ammonium hydroxide, tetra-n-butyl ammonium iodide,benzyltrimethyl ammonium chloride and quaternary phosphonium compoundssuch as, for example, n-butyltriphenyl phosphonium bromide andmethyltriphenyl phosphonium bromide.

The polycarbonates useful in the polyester compositions of the inventionalso may be copolyestercarbonates such as those described in U.S. Pat.Nos. 3,169,121; 3,207,814; 4,194,038; 4,156,069; 4,430,484, 4,465,820,and 4,981,898, the disclosure regarding copolyestercarbonates from eachof the U.S. patents is incorporated by reference herein.

Copolyestercarbonates useful in this invention can be availablecommercially and/or can be prepared by known methods in the art. Forexample, they can be typically obtained by the reaction of at least onedihydroxyaromatic compound with a mixture of phosgene and at least onedicarboxylic acid chloride, especially isophthaloyl chloride,terephthaloyl chloride, or both.

In addition, the polyester compositions and the polymer blendcompositions useful in the ophthalmic product(s) of this invention mayalso contain from 0.01 to 25% by weight of the overall compositioncommon additives such as colorants, dyes, mold release agents, flameretardants, plasticizers, nucleating agents, stabilizers, including butnot limited to, UV stabilizers, thermal stabilizers and/or reactionproducts thereof, fillers, and impact modifiers. For example, UVadditives can be incorporated into the ophthalmic product(s) throughaddition to the bulk, through application of a hard coat, or through thecoextrusion of a cap layer. Examples of typical commercially availableimpact modifiers well known in the art and useful in this inventioninclude, but are not limited to, ethylene/propylene terpolymers;functionalized polyolefins,such as those containing methyl acrylateand/or glycidyl methacrylate; styrene-based block copolymeric impactmodifiers, and various acrylic core/shell type impact modifiers.Residues of such additives are also contemplated as part of thepolyester composition.

The polyesters of the invention can comprise at least one chainextender. Suitable chain extenders include, but are not limited to,multifunctional (including, but not limited to, bifunctional)isocyanates, multifunctional epoxides, including for example, epoxylatednovolacs, and phenoxy resins. In certain embodiments, chain extendersmay be added at the end of the polymerization process or after thepolymerization process. If added after the polymerization process, chainextenders can be incorporated by compounding or by addition duringconversion processes such as injection molding or extrusion. The amountof chain extender used can vary depending on the specific monomercomposition used and the physical properties desired but is generallyfrom 0.1 percent by weight to 10 percent by weight, such as from 0.1 to5 percent by weight, based on the total weigh of the polyester.

Thermal stabilizers are compounds that stabilize polyesters duringpolyester manufacture and/or post polymerization, including, but notlimited to, phosphorous compounds, including, but not limited to,phosphoric acid, phosphorous acid, phosphonic acid, phosphinic acid,phosphonous acid, and various esters and salts thereof. The esters canbe alkyl, branched alkyl, substituted alkyl, difunctional alkyl, alkylethers, aryl, and substituted aryl. In one embodiment, the number ofester groups present in the particular phosphorous compound can varyfrom zero up to the maximum allowable based on the number of hydroxylgroups present on the thermal stabilizer used. The term “thermalstabilizer” is intended to include the reaction product(s) thereof. Theterm “reaction product” as used in connection with the thermalstabilizers of the invention refers to any product of a polycondensationor esterification reaction between the thermal stabilizer and any of themonomers used in making the polyester as well as the product of apolycondensation or esterification reaction between the catalyst and anyother type of additive. These can be present in the polyestercompositions useful in the invention.

Reinforcing materials may be useful in the compositions of thisinvention. The reinforcing materials may include, but are not limitedto, carbon filaments, silicates, mica, clay, talc, titanium dioxide,Wollastonite, glass flakes, glass beads and fibers, and polymeric fibersand combinations thereof. In one embodiment, the reinforcing materialsare glass, such as, fibrous glass filaments, mixtures of glass and talc,glass and mica, and glass and polymeric fibers.

The invention further relates to ophthalmic products described herein.These ophthalmic products include, but are not limited to, injectionmolded ophthalmic products, compression molded ophthalmic products, andsolution casted ophthalmic products. Methods of making ophthalmicproducts include, but are not limited to, injection molding, compressionmolding, and solution casting.

For the purposes of this disclosure, the term “wt” means “weight”.

The following examples further illustrate how the ophthalmic product(s)of the invention can be made and evaluated, and are intended to bepurely exemplary of the invention and are not intended to limit thescope thereof. Unless indicated otherwise, parts are parts by weight,temperature is in degrees C or is at room temperature, and pressure isat or near atmospheric.

EXAMPLES

Measurement Methods

The inherent viscosity of the polyesters was determined in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.

Unless stated otherwise, the glass transition temperature (T_(g)) wasdetermined using a TA DSC 2920 instrument from Thermal AnalystInstruments at a scan rate of 20° C./min according to ASTM D3418.

The glycol content and the cis/trans ratio of the compositions weredetermined by proton nuclear magnetic resonance (NMR) spectroscopy. AllNMR spectra were recorded on a JEOL Eclipse Plus 600 MHz nuclearmagnetic resonance spectrometer using either chloroform-trifluoroaceticacid (70-30 volume/volume) for polymers or, for oligomeric samples,60/40(wt/wt) phenol/tetrachloroethane with deuterated chloroform addedfor lock. Peak assignments for 2,2,4,4-tetramethyl-1,3-cyclobutanediolresonances were made by comparison to model mono- and dibenzoate estersof 2,2,4,4-tetramethyl-1,3-cyclobutanediol. These model compoundsclosely approximate the resonance positions found in the polymers andoligomers.

The crystallization half-time, t1/2, was determined by measuring thelight transmission of a sample via a laser and photo detector as afunction of time on a temperature controlled hot stage. This measurementwas done by exposing the polymers to a temperature, T_(max), and thencooling it to the desired temperature. The sample was then held at thedesired temperature by a hot stage while transmission measurements weremade as a function of time. Initially, the sample was visually clearwith high light transmission and became opaque as the samplecrystallized. The crystallization half-time was recorded as the time atwhich the light transmission was halfway between the initialtransmission and the final transmission. T_(max) is defined as thetemperature required to melt the crystalline domains of the sample (ifcrystalline domains are present). The T_(max) reported in the examplesbelow represents the temperature at which each sample was heated tocondition the sample prior to crystallization half time measurement. TheT_(max) temperature is dependant on composition and is typicallydifferent for each polyester. For example, PCT may need to be heated tosome temperature greater than 290° C. to melt the crystalline domains.

Density was determined using a gradient density column at 23° C.

The melt viscosity reported herein was measured by using a RheometricsDynamic Analyzer (RDA II). The melt viscosity was measured as a functionof shear rate, at frequencies ranging from 1 to 400 rad/sec, at thetemperatures reported. The zero shear melt viscosity (η_(o)) is the meltviscosity at zero shear rate estimated by extrapolating the data byknown models in the art. This step is automatically performed by theRheometrics Dynamic Analyzer (RDA II) software.

The polymers were dried at a temperature ranging from 80 to 100° C. in avacuum oven for 24 hours and injection molded on a Boy 22S moldingmachine to give ⅛×½×5-inch and ¼×½×5-inch flexure bars. These bars werecut to a length of 2.5 inch and notched down the ½ inch width with a10-mil notch in accordance with ASTM D256. The average Izod impactstrength at 23° C. was determined from measurements on 5 specimens.

In addition, 5 specimens were tested at various temperatures using 5° C.increments in order to determine the brittle-to-ductile transitiontemperature. The brittle-to-ductile transition temperature is defined asthe temperature at which 50% of the specimens fail in a brittle manneras denoted by ASTM D256.

Color values reported herein were determined using a Hunter LabUltrascan Spectra Colorimeter manufactured by Hunter Associates LabInc., Reston, Va. The color determinations were averages of valuesmeasured on either pellets of the polyesters or plaques or other itemsinjection molded or extruded from them. They were determined by theL*a*b* color system of the CIE (International Commission onIllumination) (translated), wherein L* represents the lightnesscoordinate, a* represents the red/green coordinate, and b* representsthe yellow/blue coordinate.

In addition, 10-mil films were compression molded using a Carver pressat 240° C.

Unless otherwise specified, the cis/trans ratio of the 1,4cyclohexanedimethanol used in the following examples was approximately30/70, and could range from 35/65 to 25/75. Unless otherwise specified,the cis/trans ratio of the 2,2,4,4-tetramethyl-1,3-cyclobutanediol usedin the following examples was approximately 50/50.

The following abbreviations apply throughout the working examples andfigures: TPA Terephthalic acid DMT Dimethyl terephthalate TMCD2,2,4,4-tetramethyl-1,3-cyclobutanediol CHDM 1,4-cyclohexanedimethanolIV Inherent viscosity η₀ Zero shear melt viscosity T_(g) Glasstransition temperature T_(bd) Brittle-to-ductile transition temperatureT_(max) Conditioning temperature for crystallization half timemeasurements

Example 1

This example illustrates that 2,2,4,4-tetramethyl-1,3-cyclobutanediol ismore effective at reducing the crystallization rate of PCT than ethyleneglycol or isophthalic acid. In addition, this example illustrates thebenefits of 2,2,4,4-tetramethyl-1,3-cyclobutanediol on the glasstransition temperature and density.

A variety of copolyesters were prepared as described below. Thesecopolyesters were all made with 200 ppm dibutyl tin oxide as thecatalyst in order to minimize the effect of catalyst type andconcentration on nucleation during crystallization studies. Thecis/trans ratio of the 1,4-cyclohexanedimethanol was 31/69 while thecis/trans ratio of the 2,2,4,4-tetramethyl-1,3-cyclobutanediol isreported in Table 1.

For purposes of this example, the samples had sufficiently similarinherent viscosities thereby effectively eliminating this as a variablein the crystallization rate measurements.

Crystallization half-time measurements from the melt were made attemperatures from 140 to 200° C. at 10° C. increments and are reportedin Table 1. The fastest crystallization half-time for each sample wastaken as the minimum value of crystallization half-time as a function oftemperature, typically occurring around 170 to 180° C. The fastestcrystallization half-times for the samples are plotted in FIG. 1 as afunction of mole % comonomer modification to PCT.

The data shows that 2,2,4,4-tetramethyl-1,3-cyclobutanediol is moreeffective than ethylene glycol and isophthalic acid at decreasing thecrystallization rate (i.e., increasing the crystallization half-time).In addition, 2,2,4,4-tetramethyl-1,3-cyclobutanediol increases T_(g) andlowers density. TABLE 1 Crystallization Half-times (min) at at at at atat at Comonomer IV Density T_(g) T_(max) 140° C. 150° C. 160° C. 170° C.180° C. 190° C. 200° C. Example (mol %)¹ (dl/g) (g/ml) (° C.) (° C.)(min) (min) (min) (min) (min) (min) (min) 1A 20.2% A² 0.630 1.198 87.5290 2.7 2.1 1.3 1.2 0.9 1.1 1.5 1B 19.8% B 0.713 1.219 87.7 290 2.3 2.51.7 1.4 1.3 1.4 1.7 1C 20.0% C 0.731 1.188 100.5 290 >180 >60 35.0 23.321.7 23.3 25.2 1D 40.2% A² 0.674 1.198 81.2 260 18.7 20.0 21.3 25.0 34.059.9 96.1 1E 34.5% B 0.644 1.234 82.1 260 8.5 8.2 7.3 7.3 8.3 10.0 11.41F 40.1% C 0.653 1.172 122.0 260 >10 days >5 days >5 days 19204 >5days >5 days >5 days 1G 14.3% D 0.646³ 1.188 103.0 290 55.0 28.8 11.66.8 4.8 5.0 5.5 1H 15.0% E 0.728⁴ 1.189 99.0 290 25.4 17.1 8.1 5.9 4.32.7 5.1¹The balance of the diol component of the polyesters in Table 1 is1,4-cyclohexanedimethanol; and the balance of the dicarboxylic acidcomponent of the polyesters in Table 1 is dimethyl terephthalate; if thedicarboxylic acid is not described, it is 100 mole % dimethylterephthalate.²100 mole % 1,4-cyclohexanedimethanol.³A film was pressed from the ground polyester of Example 1G at 240° C.The resulting film had an inherent viscosity value of 0.575 dL/g.⁴A film was pressed from the ground polyester of Example 1H at 240° C.The resulting film had an inherent viscosity value of 0.0.652 dL/g.where:A is Isophthalic AcidB is Ethylene GlycolC is 2,2,4,4-Tetramethyl-1,3-cyclobutanediol (approx. 50/50 cis/trans)D is 2,2,4,4-Tetramethyl-1,3-cyclobutanediol (98/2 cis/trans)E is 2,2,4,4-Tetramethyl-1,3-cyclobutanediol (5/95 cis/trans)

As shown in Table 1 and FIG. 1, 2,2,4,4-tetramethyl-1,3-cyclobutanediolis more effective than other comonomers, such ethylene glycol andisophthalic acid, at increasing the crystallization half-time, i.e., thetime required for a polymer to reach half of its maximum crystallinity.By decreasing the crystallization rate of PCT (increasing thecrystallization half-time), amorphous articles based on2,2,4,4-tetramethyl-1,3-cyclobutanediol-modified PCT as described hereinmay be fabricated by methods known in the art. As shown in Table 1,these materials can exhibit higher glass transition temperatures andlower densities than other modified PCT copolyesters.

Preparation of the polyesters shown on Table 1 is described below.

Example 1A

This example illustrates the preparation of a copolyester with a targetcomposition of 80 mol % dimethyl terephthalate residues, 20 mol %dimethyl isophthalate residues, and 100 mol % 1,4-cyclohexanedimethanolresidues (28/72 cis/trans).

A mixture of 56.63 g of dimethyl terephthalate, 55.2 g of1,4-cyclohexanedimethanol, 14.16 g of dimethyl isophthalate, and 0.0419g of dibutyl tin oxide was placed in a 500-milliliter flask equippedwith an inlet for nitrogen, a metal stirrer, and a short distillationcolumn. The flask was placed in a Wood's metal bath already heated to210° C. The stirring speed was set to 200 RPM throughout the experiment.The contents of the flask were heated at 210° C. for 5 minutes and thenthe temperature was gradually increased to 290° C. over 30 minutes. Thereaction mixture was held at 290° C. for 60 minutes and then vacuum wasgradually applied over the next 5 minutes until the pressure inside theflask reached 100 mm of Hg. The pressure inside the flask was furtherreduced to 0.3 mm of Hg over the next 5 minutes. A pressure of 0.3 mm ofHg was maintained for a total time of 90 minutes to remove excessunreacted diols. A high melt viscosity, visually clear and colorlesspolymer was obtained with a glass transition temperature of 87.5° C. andan inherent viscosity of 0.63 dl/g. NMR analysis showed that the polymerwas composed of 100 mol % 1,4-cyclohexanedimethanol residues and 20.2mol % dimethyl isophthalate residues.

Example 1B

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 20 mol %ethylene glycol residues, and 80 mol % 1,4-cyclohexanedimethanolresidues (32/68 cis/trans).

A mixture of 77.68 g of dimethyl terephthalate, 50.77 g of1,4-cyclohexanedimethanol, 27.81 g of ethylene glycol, and 0.0433 g ofdibutyl tin oxide was placed in a 500-milliliter flask equipped with aninlet for nitrogen, a metal stirrer, and a short distillation column.The flask was placed in a Wood's metal bath already heated to 200° C.The stirring speed was set to 200 RPM throughout the experiment. Thecontents of the flask were heated at 200° C. for 60 minutes and then thetemperature was gradually increased to 210° C. over 5 minutes. Thereaction mixture was held at 210° C. for 120 minutes and then heated upto 280° C. in 30 minutes. Once at 280° C., vacuum was gradually appliedover the next 5 minutes until the pressure inside the flask reached 100mm of Hg. The pressure inside the flask was further reduced to 0.3 mm ofHg over the next 10 minutes. A pressure of 0.3 mm of Hg was maintainedfor a total time of 90 minutes to remove excess unreacted diols. A highmelt viscosity, visually clear and colorless polymer was obtained with aglass transition temperature of 87.7° C. and an inherent viscosity of0.71 dl/g. NMR analysis showed that the polymer was composed of 19.8 mol% ethylene glycol residues.

Example 1C

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 20 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues, and 80 mol %1,4-cyclohexanedimethanol residues (31/69 cis/trans).

A mixture of 77.68 g of dimethyl terephthalate, 48.46 g of1,4-cyclohexanedimethanol, 17.86 g of2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 0.046 g of dibutyl tinoxide was placed in a 500-milliliter flask equipped with an inlet fornitrogen, a metal stirrer, and a short distillation column. Thispolyester was prepared in a manner similar to that described in Example1A. A high melt viscosity, visually clear and colorless polymer wasobtained with a glass transition temperature of 100.5° C. and aninherent viscosity of 0.73 dl/g. NMR analysis showed that the polymerwas composed of 80.5 mol % 1,4-cyclohexanedimethanol residues and 19.5mol % 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Example 1D

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 40 mol %dimethyl isophthalate residues, and 100 mol % 1,4-cyclohexanedimethanolresidues (28/72 cis/trans).

A mixture of 42.83 g of dimethyl terephthalate, 55.26 g of1,4-cyclohexanedimethanol, 28.45 g of dimethyl isophthalate, and 0.0419g of dibutyl tin oxide was placed in a 500-milliliter flask equippedwith an inlet for nitrogen, a metal stirrer, and a short distillationcolumn. The flask was placed in a Wood's metal bath already heated to210° C. The stirring speed was set to 200 RPM throughout the experiment.The contents of the flask were heated at 210° C. for 5 minutes and thenthe temperature was gradually increased to 290° C. over 30 minutes. Thereaction mixture was held at 290° C. for 60 minutes and then vacuum wasgradually applied over the next 5 minutes until the pressure inside theflask reached 100 mm of Hg. The pressure inside the flask was furtherreduced to 0.3 mm of Hg over the next 5 minutes. A pressure of 0.3 mm ofHg was maintained for a total time of 90 minutes to remove excessunreacted diols. A high melt viscosity, visually clear and colorlesspolymer was obtained with a glass transition temperature of 81.2° C. andan inherent viscosity of 0.67 dl/g. NMR analysis showed that the polymerwas composed of 100 mol % 1,4-cyclohexanedimethanol residues and 40.2mol % dimethyl isophthalate residues.

Example 1E

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 40 mol %ethylene glycol residues, and 60 mol % 1,4-cyclohexanedimethanolresidues (31/69 cis/trans).

A mixture of 81.3 g of dimethyl terephthalate, 42.85 g of1,4-cyclohexanedimethanol, 34.44 g of ethylene glycol, and 0.0419 g ofdibutyl tin oxide was placed in a 500-milliliter flask equipped with aninlet for nitrogen, a metal stirrer, and a short distillation column.The flask was placed in a Wood's metal bath already heated to 200° C.The stirring speed was set to 200 RPM throughout the experiment. Thecontents of the flask were heated at 200° C. for 60 minutes and then thetemperature was gradually increased to 210° C. over 5 minutes. Thereaction mixture was held at 210° C. for 120 minutes and then heated upto 280° C. in 30 minutes. Once at 280° C., vacuum was gradually appliedover the next 5 minutes until the pressure inside the flask reached 100mm of Hg. The pressure inside the flask was further reduced to 0.3 mm ofHg over the next 10 minutes. A pressure of 0.3 mm of Hg was maintainedfor a total time of 90 minutes to remove excess unreacted diols. A highmelt viscosity, visually clear and colorless polymer was obtained with aglass transition temperature of 82.1° C. and an inherent viscosity of0.64 dl/g. NMR analysis showed that the polymer was composed of 34.5 mol% ethylene glycol residues.

Example 1F

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 40 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues, and 60 mol %1,4-cyclohexanedimethanol residues (31/69 cis/trans).

A mixture of 77.4 g of dimethyl terephthalate, 36.9 g of1,4-cyclohexanedimethanol, 32.5 g of2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 0.046 g of dibutyl tinoxide was placed in a 500-milliliter flask equipped with an inlet fornitrogen, a metal stirrer, and a short distillation column. The flaskwas placed in a Wood's metal bath already heated to 210° C. The stirringspeed was set to 200 RPM throughout the experiment. The contents of theflask were heated at 210° C. for 3 minutes and then the temperature wasgradually increased to 260° C. over 30 minutes. The reaction mixture washeld at 260° C. for 120 minutes and then heated up to 290° C. in 30minutes. Once at 290° C., vacuum was gradually applied over the next 5minutes until the pressure inside the flask reached 100 mm of Hg. Thepressure inside the flask was further reduced to 0.3 mm of Hg over thenext 5 minutes. A pressure of 0.3 mm of Hg was maintained for a totaltime of 90 minutes to remove excess unreacted diols. A high meltviscosity, visually clear and colorless polymer was obtained with aglass transition temperature of 122° C. and an inherent viscosity of0.65 dl/g. NMR analysis showed that the polymer was composed of 59.9 mol% 1,4-cyclohexanedimethanol residues and 40.1 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Example 1G

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 20 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues (98/2 cis/trans), and80 mol % 1,4-cyclohexanedimethanol residues (31/69 cis/trans).

A mixture of 77.68 g of dimethyl terephthalate, 48.46 g of1,4-cyclohexanedimethanol, 20.77 g of2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 0.046 g of dibutyl tinoxide was placed in a 500-milliliter flask equipped with an inlet fornitrogen, a metal stirrer, and a short distillation column. The flaskwas placed in a Wood's metal bath already heated to 210° C. The stirringspeed was set to 200 RPM throughout the experiment. The contents of theflask were heated at 210° C. for 3 minutes and then the temperature wasgradually increased to 260° C. over 30 minutes. The reaction mixture washeld at 260° C. for 120 minutes and then heated up to 290° C. in 30minutes. Once at 290° C., vacuum was gradually applied over the next 5minutes until the pressure inside the flask reached 100 mm of Hg and thestirring speed was also reduced to 100 RPM. The pressure inside theflask was further reduced to 0.3 mm of Hg over the next 5 minutes andthe stirring speed was reduced to 50 RPM. A pressure of 0.3 mm of Hg wasmaintained for a total time of 60 minutes to remove excess unreacteddiols. A high melt viscosity, visually clear and colorless polymer wasobtained with a glass transition temperature of 103° C. and an inherentviscosity of 0.65 dl/g. NMR analysis showed that the polymer wascomposed of 85.7 mol % 1,4-cyclohexanedimethanol residues and 14.3 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Example 1H

This example illustrates the preparation of a copolyester with a targetcomposition of 100 mol % dimethyl terephthalate residues, 20 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues (5/95 cis/trans), and80 mol % 1,4-cyclohexanedimethanol residues (31/69 cis/trans).

A mixture of 77.68 g of dimethyl terephthalate, 48.46 g of1,4-cyclohexanedimethanol, 20.77 g of2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 0.046 g of dibutyl tinoxide was placed in a 500-milliliter flask equipped with an inlet fornitrogen, a metal stirrer, and a short distillation column. The flaskwas placed in a Wood's metal bath already heated to 210° C. The stirringspeed was set to 200 RPM at the beginning of the experiment. Thecontents of the flask were heated at 210° C. for 3 minutes and then thetemperature was gradually increased to 260° C. over 30 minutes. Thereaction mixture was held at 260° C. for 120 minutes and then heated upto 290° C. in 30 minutes. Once at 290° C., vacuum was gradually appliedover the next 5 minutes with a set point of 100 mm of Hg and thestirring speed was also reduced to 100 RPM. The pressure inside theflask was further reduced to a set point of 0.3 mm of Hg over the next 5minutes and the stirring speed was reduced to 50 RPM. This pressure wasmaintained for a total time of 60 minutes to remove excess unreacteddiols. It was noted that the vacuum system failed to reach the set pointmentioned above, but produced enough vacuum to produce a high meltviscosity, visually clear and colorless polymer with a glass transitiontemperature of 99° C. and an inherent viscosity of 0.73 dl/g. NMRanalysis showed that the polymer was composed of 85 mol %1,4-cyclohexanedimethanol residues and 15 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Example 2

This example illustrates that 2,2,4,4-tetramethyl-1,3-cyclobutanediolimproves the toughness of PCT-based copolyesters (polyesters containingterephthalic acid and 1,4-cyclohexanedimethanol).

Copolyesters based on 2,2,4,4-tetramethyl-1,3-cyclobutanediol wereprepared as described below. The cis/trans ratio of the1,4-cyclohexanedimethanol was approximately 31/69 for all samples.Copolyesters based on ethylene glycol and 1,4-cyclohexanedimethanol werecommercial polyesters. The copolyester of Example 2A (Eastar PCTG 5445)was obtained from Eastman Chemical Co. The copolyester of Example 2B wasobtained from Eastman Chemical Co. under the trade name Spectar. Example2C and Example 2D were prepared on a pilot plant scale (each a 15-lbbatch) following an adaptation of the procedure described in Example 1Aand having the inherent viscosities and glass transition temperaturesdescribed in Table 2 below. Example 2C was prepared with a target tinamount of 300 ppm (Dibutyltin Oxide). The final product contained 295ppm tin. The color values for the polyester of Example 2C were L*=77.11;a*=−1.50; and b*=5.79. Example 2D was prepared with a target tin amountof 300 ppm (Dibutyltin Oxide). The final product contained 307 ppm tin.The color values for the polyester of Example 2D were L*=66.72;a*=−1.22; and b*=16.28.

Materials were injection molded into bars and subsequently notched forIzod testing. The notched Izod impact strengths were obtained as afunction of temperature and are also reported in Table 2.

For a given sample, the Izod impact strength undergoes a majortransition in a short temperature span. For instance, the Izod impactstrength of a copolyester based on 38 mol % ethylene glycol undergoesthis transition between 15 and 20° C. This transition temperature isassociated with a change in failure mode; brittle/low energy failures atlower temperatures and ductile/high energy failures at highertemperatures. The transition temperature is denoted as thebrittle-to-ductile transition temperature, T_(bd), and is a measure oftoughness. T_(bd) is reported in Table 2 and plotted against mol %comonomer in FIG. 2.

The data shows that adding 2,2,4,4-tetramethyl-1,3-cyclobutanediol toPCT lowers T_(bd) and improves the toughness, as compared to ethyleneglycol, which increases T_(bd) of PCT. TABLE 2 Notched Izod ImpactEnergy (ft-lb/in) Comonomer IV (dl/ T_(g) T_(bd) at at at at at at at atat at at Example (mol %)¹ g) (° C.) (° C.) −20° C. −15° C. −10° C. −5°C. 0° C. 5° C. 10° C. 15° C. 20° C. 25° C. 30° C. 2A 38.0% B 0.68 86 18NA NA NA 1.5 NA NA 1.5 1.5 32 32 NA 2B 69.0% B 0.69 82 26 NA NA NA NA NANA 2.1 NA 2.4 13.7 28.7 2C 22.0% C 0.66 106 −5 1.5 NA 12 23 23 NA 23 NANA NA NA 2D 42.8% C 0.60 133 −12 2.5 2.5 11 NA 14 NA NA NA NA NA NA¹The balance of the glycol component of the polyesters in the Table is1,4-cyclohexanedimethanol. All polymers were prepared from 100 mole %dimethyl terephthalate.NA = Not available.where:B is Ethylene glycolC is 2,2,4,4-Tetramethyl-1,3-cyclobutanediol (50/50 cis/trans)

Example 3

This example illustrates that 2,2,4,4-tetramethyl-1,3-cyclobutanediolcan improve the toughness of PCT-based copolyesters(polyesterscontaining terephthalic acid and 1,4-cyclohexanedimethanol). Polyestersprepared in this example comprise from 15 to 25 mol % of2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Copolyesters based on dimethyl terephthalate,2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 1,4-cyclohexanedimethanolwere prepared as described below, having the composition and propertiesshown on Table 3. The balance up to 100 mol % of the diol component ofthe polyesters in Table 3 was 1,4-cyclohexanedimethanol (31/69cis/trans).

Materials were injection molded into both 3.2 mm and 6.4 mm thick barsand subsequently notched for Izod impact testing. The notched Izodimpact strengths were obtained at 23° C. and are reported in Table 3.Density, Tg, and crystallization halftime were measured on the moldedbars. Melt viscosity was measured on pellets at 290° C. TABLE 3Compilation of various properties for certain polyesters useful in theinvention Notched Notched Izod of Izod of 3.2 mm 6.4 mm Melt thick thickCrystallization Viscosity Pellet Molded bars at bars at SpecificHalftime from at 1 rad/sec TMCD % cis IV Bar IV 23° C. 23° C. Gravity Tgmelt at 170° C. at 290° C. Example mole % TMCD (dl/g) (dl/g) (J/m) (J/m)(g/mL) (° C.) (min) (Poise) A 15 48.8 0.736 0.707 1069 878 1.184 104 155649 B 18 NA 0.728 0.715 980 1039 1.183 108 22 6621 C 20 NA 0.706 0.6961006 1130 1.182 106 52 6321 D 22 NA 0.732 0.703 959 988 1.178 108 637161 E 21 NA 0.715 0.692 932 482 1.179 110 56 6162 F 24 NA 0.708 0.677976 812 1.180 109 58 6282 G 23 NA 0.650 0.610 647 270 1.182 107 46 3172H 23 47.9 0.590 0.549 769 274 1.181 106 47 1736 I 23 48.1 0.531 0.516696 352 1.182 105 19 1292NA = Not available

Example 3A

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 14.34 lb (45.21gram-mol) 1,4-cyclohexanedimethanol, and 4.58 lb (14.44 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and at a pressure of 20 psig. The pressure was thendecreased to 0 psig at a rate of 3 psig/minute. The temperature of thereaction mixture was then increased to 270° C. and the pressure wasdecreased to 90 mm of Hg. After a 1 hour hold time at 270° C. and 90 mmof Hg, the agitator speed was decreased to 15 RPM, the reaction mixturetemperature was increased to 290° C., and the pressure was decreased to<1 mm of Hg. The reaction mixture was held at 290° C. and at a pressureof <1 mm of Hg until the power draw to the agitator no longer increased(70 minutes). The pressure of the pressure vessel was then increased to1 atmosphere using nitrogen gas. The molten polymer was then extrudedfrom the pressure vessel. The cooled, extruded polymer was ground topass a 6-mm screen. The polymer had an inherent viscosity of 0.736 dL/gand a Tg of 104° C. NMR analysis showed that the polymer was composed of85.4 mol % 1,4-cyclohexanedimethanol residues and 14.6 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues. The polymer had colorvalues of: L*=78.20, a*=−1.62, and b*=6.23.

Example 3B to Example 3D

The polyesters described in Example 3B to Example 3D were preparedfollowing a procedure similar to the one described for Example 3A. Thecomposition and properties of these polyesters are shown in Table 3.

Example 3E

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 12.61 lb (39.77gram-mol) 1,4-cyclohexanedimethanol, and 6.30 lb (19.88 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and 20 psig pressure. The pressure was then decreasedto 0 psig at a rate of 3 psig/minute. The temperature of the reactionmixture was then increased to 270° C. and the pressure was decreased to90 mm of Hg. After a 1 hour hold time at 270° C. and 90 mm of Hg, theagitator speed was decreased to 15 RPM, the reaction mixture temperaturewas increased to 290° C., and the pressure was decreased to <1 mm of Hg.The reaction mixture was held at 290° C. and at a pressure of <1 mm ofHg for 60 minutes. The pressure of the pressure vessel was thenincreased to 1 atmosphere using nitrogen gas. The molten polymer wasthen extruded from the pressure vessel. The cooled, extruded polymer wasground to pass a 6-mm screen. The polymer had an inherent viscosity of0.715 dL/g and a Tg of 110° C. X-ray analysis showed that the polyesterhad 223 ppm tin. NMR analysis showed that the polymer was composed of78.6 mol % 1,4-cyclohexanedimethanol residues and 21.4 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues. The polymer had colorvalues of: L*=76.45, a*=−1.65, and b*=6.47.

Example 3F

The polyester described in Example 3F was prepared following a proceduresimilar to the one described for Example 3A. The composition andproperties of this polyester are shown in Table 3.

Example 3H

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 12.61 lb (39.77gram-mol) 1,4-cyclohexanedimethanol, and 6.30 lb (19.88 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and 20 psig pressure. The pressure was then decreasedto 0 psig at a rate of 3 psig/minute. The temperature of the reactionmixture was then increased to 270° C. and the pressure was decreased to90 mm of Hg. After a 1 hour hold time at 270° C. and 90 mm of Hg, theagitator speed was decreased to 15 RPM, the reaction mixture temperaturewas increased to 290° C., and the pressure was decreased to <1 mm of Hg.The reaction mixture was held at 290° C. and at a pressure of <1 mm ofHg for 12 minutes. The pressure of the pressure vessel was thenincreased to 1 atmosphere using nitrogen gas. The molten polymer wasthen extruded from the pressure vessel. The cooled, extruded polymer wasground to pass a 6-mm screen. The polymer had an inherent viscosity of0.590 dL/g and a Tg of 106° C. NMR analysis showed that the polymer wascomposed of 77.1 mol % 1,4-cyclohexane-dimethanol residues and 22.9 mol% 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues. The polymer hadcolor values of: L*=83.27, a*=−1.34, and b*=5.08.

Example 3I

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 12.61 lb (39.77gram-mol) 1,4-cyclohexanedimethanol, and 6.30 lb (19.88 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and 20 psig pressure. The pressure was then decreasedto 0 psig at a rate of 3 psig/minute. The temperature of the reactionmixture was then increased to 270° C. and the pressure was decreased to90 mm of Hg. After a 1 hour hold time at 270° C. and 90 mm of Hg, theagitator speed was decreased to 15 RPM, the reaction mixture temperaturewas increased to 290° C., and the pressure was decreased to 4 mm of Hg.The reaction mixture was held at 290° C. and at a pressure of 4 mm of Hgfor 30 minutes. The pressure of the pressure vessel was then increasedto 1 atmosphere using nitrogen gas. The molten polymer was then extrudedfrom the pressure vessel. The cooled, extruded polymer was ground topass a 6-mm screen. The polymer had an inherent viscosity of 0.531 dL/gand a Tg of 105° C. NMR analysis showed that the polymer was composed of76.9 mol % 1,4-cyclohexane-dimethanol residues and 23.1 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues. The polymer had colorvalues of: L*=80.42, a*=−1.28, and b*=5.13.

Example 4

This example illustrates that 2,2,4,4-tetramethyl-1,3-cyclobutanediolcan improve the toughness of PCT-based copolyesters(polyesterscontaining terephthalic acid and 1,4-cyclohexanedimethanol). Polyestersprepared in this example fall comprise more than 25 to less than 40 mol% of 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Copolyesters based on dimethyl terephthalate,2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 1,4-cyclohexanedimethanol(31/69 cis/trans) were prepared as described below, having thecomposition and properties shown on Table 4. The balance up to 100 mol %of the diol component of the polyesters in Table 4 was1,4-cyclohexanedimethanol (31/69 cis/trans).

Materials were injection molded into both 3.2 mm and 6.4 mm thick barsand subsequently notched for Izod impact testing. The notched Izodimpact strengths were obtained at 23° C. and are reported in Table 4.Density, Tg, and crystallization halftime were measured on the moldedbars. Melt viscosity was measured on pellets at 290° C. TABLE 4Compilation of various properties for certain polyesters useful in theinvention Notched Notched Izod of Izod of 3.2 mm 6.4 mm Melt thick thickCrystallization Viscosity Pellet Molded bars at bars at SpecificHalftime from at 1 rad/sec TMCD % cis IV Bar IV 23° C. 23° C. Gravity Tgmelt at 170° C. at 290° C. Example mole % TMCD (dl/g) (dl/g) (J/m) (J/m)(g/mL) (° C.) (min) (Poise) A 27 47.8 0.714 0.678 877 878 1.178 113 2808312 B 31 NA 0.667 0.641 807 789 1.174 116 600 6592NA = Not available

Example 4A

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 11.82 lb (37.28gram-mol) 1,4-cyclohexanedimethanol, and 6.90 lb (21.77 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and 20 psig pressure. The pressure was then decreasedto 0 psig at a rate of 3 psig/minute. The temperature of the reactionmixture was then increased to 270° C. and the pressure was decreased to90 mm of Hg. After a 1 hour hold time at 270° C. and 90 mm of Hg, theagitator speed was decreased to 15 RPM, the reaction mixture temperaturewas increased to 290° C., and the pressure was decreased to <1 mm of Hg.The reaction mixture was held at 290° C. and at a pressure of <1 mm ofHg until the power draw to the agitator no longer increased (50minutes). The pressure of the pressure vessel was then increased to 1atmosphere using nitrogen gas. The molten polymer was then extruded fromthe pressure vessel. The cooled, extruded polymer was ground to pass a6-mm screen. The polymer had an inherent viscosity of 0.714 dL/g and aTg of 113° C. NMR analysis showed that the polymer was composed of 73.3mol % 1,4-cyclohexane-dimethanol residues and 26.7 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Example 4B

The polyester of Example 4B was prepared following a procedure similarto the one described for Example 4A. The composition and properties ofthis polyester are shown in Table 4.

Example 5

This example illustrates that 2,2,4,4-tetramethyl-1,3-cyclobutanediolcan improve the toughness of PCT-based copolyesters (polyesterscontaining terephthalic acid and 1,4-cyclohexanedimethanol). Polyestersprepared in this example comprise2,2,4,4-tetramethyl-1,3-cyclobutanediol residues in an amount of 40 mol% or greater.

Copolyesters based on dimethyl terephthalate,2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 1,4-cyclohexanedimethanolwere prepared as described below, having the composition and propertiesshown on Table 5. The balance up to 100 mol % of the diol component ofthe polyesters in Table 5 was 1,4-cyclohexanedimethanol (31/69cis/trans).

Materials were injection molded into both 3.2 mm and 6.4 mm thick barsand subsequently notched for Izod impact testing. The notched Izodimpact strengths were obtained at 23° C. and are reported in Table 5.Density, Tg, and crystallization halftime were measured on the moldedbars. Melt viscosity was measured on pellets at 290° C. TABLE 5Compilation of various properties for certain polyesters useful in theinvention Notched Notched Izod of Izod of 3.2 mm 6.4 mm Melt thick thickCrystallization Viscosity Pellet Molded bars at bars at SpecificHalftime from at 1 rad/sec TMCD % cis IV Bar IV 23° C. 23° C. Gravity Tgmelt at 170° C. at 290° C. Example mole % TMCD (dl/g) (dl/g) (J/m) (J/m)(g/mL) (° C.) (min) (Poise) A 44 46.2 0.657 0.626 727 734 1.172 119 NA9751 B 45 NA 0.626 0.580 748 237 1.167 123 NA 8051 C 45 NA 0.582 0.550671 262 1.167 125 19782 5835 D 45 NA 0.541 0.493 424 175 1.167 123 NA3275 E 59 46.6 0.604 0.576 456 311 1.156 139 NA 16537 F 45 47.2 0.4750.450 128 30 1.169 121 NA 1614NA = Not available

Example 5A

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 8.84 lb (27.88gram-mol) 1,4-cyclohexanedimethanol, and 10.08 lb (31.77 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and 20 psig pressure. The pressure was then decreasedto 0 psig at a rate of 3 psig/minute. Then the agitator speed wasdecreased to 15 RPM, the temperature of the reaction mixture was thenincreased to 290° C. and the pressure was decreased to 2 mm of Hg. Thereaction mixture was held at 290° C. and at a pressure of 2 mm of Hguntil the power draw to the agitator no longer increased (80 minutes).The pressure of the pressure vessel was then increased to 1 atmosphereusing nitrogen gas. The molten polymer was then extruded from thepressure vessel. The cooled, extruded polymer was ground to pass a 6-mmscreen. The polymer had an inherent viscosity of 0.657 dL/g and a Tg of119° C. NMR analysis showed that the polymer was composed of 56.3 mol %1,4-cyclohexane-dimethanol residues and 43.7 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues. The polymer had colorvalues of: L*=75.04, a*=−1.82, and b*=6.72.

Example 5B to Example 5D

The polyesters described in Example 5B to Example 5D were preparedfollowing a procedure similar to the one described for Example 5A. Thecomposition and properties of these polyesters are shown in Table 5.

Example 5E

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 6.43 lb (20.28gram-mol 1,4-cyclohexanedimethanol, and 12.49 lb (39.37 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and 20 psig pressure. The pressure was then decreasedto 0 psig at a rate of 3 psig/minute. Then the agitator speed wasdecreased to 15 RPM, the temperature of the reaction mixture was thenincreased to 290° C. and the pressure was decreased to 2 mm of Hg. Thereaction mixture was held at 290° C. and at a pressure of <1 mm of Hguntil the power draw to the agitator no longer increased (50 minutes).The pressure of the pressure vessel was then increased to 1 atmosphereusing nitrogen gas. The molten polymer was then extruded from thepressure vessel. The cooled, extruded polymer was ground to pass a 6-mmscreen. The polymer had an inherent viscosity of 0.604 dL/g and a Tg of139° C. NMR analysis showed that the polymer was composed of 40.8 mol %1,4-cyclohexanedimethanol residues and 59.2 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues. The polymer had colorvalues of: L*=80.48, a*=−1.30, and b*=6.82.

Example 5F

21.24 lb (49.71 gram-mol) dimethyl terephthalate, 8.84 lb (27.88gram-mol) 1,4-cyclohexanedimethanol, and 10.08 lb (31.77 gram-mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol were reacted together in thepresence of 200 ppm of the catalyst butyltin tris(2-ethylhexanoate). Thereaction was carried out under a nitrogen gas purge in an 18-gallonstainless steel pressure vessel fitted with a condensing column, avacuum system, and a HELICONE-type agitator. With the agitator runningat 25 RPM, the reaction mixture temperature was increased to 250° C. andthe pressure was increased to 20 psig. The reaction mixture was held for2 hours at 250° C. and 20 psig pressure. The pressure was then decreasedto 0 psig at a rate of 3 psig/minute. The temperature of the reactionmixture was then increased to 270° C. and the pressure was decreased to90 mm of Hg. After a 1 hour hold time at 270° C. and 90 mm of Hg, theagitator speed was decreased to 15 RPM and the pressure was decreased to4 mm of Hg. When the reaction mixture temperature was 270° C. and thepressure was 4 mm of Hg, the pressure of the pressure vessel wasimmediately increased to 1 atmosphere using nitrogen gas. The moltenpolymer was then extruded from the pressure vessel. The cooled, extrudedpolymer was ground to pass a 6-mm screen. The polymer had an inherentviscosity of 0.475 dL/g and a Tg of 121° C. NMR analysis showed that thepolymer was composed of 55.5 mol % 1,4-cyclohexane-dimethanol residuesand 44.5 mol % 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues. Thepolymer had color values of: L*=85.63, a*=−0.88, and b*=4.34.

Example 6 Comparative Example

This example shows data for comparative materials in Table 6. The PC wasMakrolon 2608 from Bayer, with a nominal composition of 100 mole %bisphenol A residues and 100 mole % diphenyl carbonate residues.Makrolon 2608 has a nominal melt flow rate of 20 grams/10 minutesmeasured at 300 C using a 1.2 kg weight. The PET was Eastar 9921 fromEastman Chemical Company, with a nominal composition of 100 mole %terephthalic acid, 3.5 mole % cyclohexanedimethanol (CHDM) and 96.5 mole% ethylene glycol. The PETG was Eastar 6763 from Eastman ChemicalCompany, with a nominal composition of 100 mole % terephthalic acid, 31mole % cyclohexanedimethanol (CHDM) and 69 mole % ethylene glycol. ThePCTG was Eastar DN001 from Eastman Chemical Company, with a nominalcomposition of 100 mole % terephthalic acid, 62 mole %cyclohexanedimethanol (CHDM) and 38 mole % ethylene glycol. The PCTA wasEastar AN001 from Eastman Chemical Company, with a nominal compositionof 65 mole % terephthalic acid, 35 mole % isophthalic acid and 100 mole% cyclohexanedimethanol (CHDM). The Polysulfone was Udel 1700 fromSolvay, with a nominal composition of 100 mole % bisphenol A residuesand 100 mole % 4,4-dichlorosulfonyl sulfone residues. Udel 1700 has anominal melt flow rate of 6.5 grams/10 minutes measured at 343 C using a2.16 kg weight. The SAN was Lustran 31 from Lanxess, with a nominalcomposition of 76 weight % styrene and 24 weight % acrylonitrile.Lustran 31 has a nominal melt flow rate of 7.5 grams/10 minutes measuredat 230 C using a 3.8 kg weight. The examples of the invention showimproved toughness in 6.4 mm thickness bars compared to all of the otherresins. TABLE 6 Compilation of various properties for certain commercialpolymers Notched Notched Izod of Izod of 3.2 mm 6.4 mm thick thickCrystallization Pellet Molded bars at bars at Specific Halftime fromPolymer IV Bar IV 23° C. 23° C. Gravity Tg melt Example name (dl/g)(dl/g) (J/m) (J/m) (g/mL) (° C.) (min) A PC  12 MFR NA 929  108 1.20 146NA B PCTG 0.73 0.696 NB 70 1.23 87 30 at 170° C. C PCTA 0.72 0.702 98 591.20 87 15 at 150° C. D PETG 0.75 0.692 83 59 1.27 80 2500 at 130° C.  EPET 0.76 0.726 45 48 1.33 78 1.5 at 170° C.  F SAN 7.5 MFR NA 21 NA 1.07˜110 NA G PSU 6.5 MFR NA 69 NA 1.24 ˜190 NANA = Not available

Example 7

This example illustrates the effect of the amount of2,2,4,4-tetramethyl-1,3-cyclobutanediol used for the preparation of thepolyesters of the invention on the glass transition temperature of thepolyesters. Polyesters prepared in this example comprise from 15 to 25mol % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

Example 7A to Example 7F

Dimethyl terephthalate, 1,4-cyclohexanedimethanol, and2,2,4,4-tetramethyl-1,3-cyclobutanediol were weighed into a 500-mlsingle neck round bottom flask. NMR analysis on the2,2,4,4-tetramethyl-1,3-cyclobutanediol starting material showed acis/trans ratio of 53/47. The polyesters of this example were preparedwith a 1.2/1 glycol/acid ratio with the entire excess coming from the2,2,4,4-tetramethyl-1,3-cyclobutanediol. Enough dibutyltin oxidecatalyst was added to give 300 ppm tin in the final polymer. The flaskwas under a 0.2 SCFC nitrogen purge with vacuum reduction capability.The flask was immersed in a Belmont metal bath at 200° C. and stirred at200 RPM after the reactants had melted. After about 2.5 hours, thetemperature was raised to 210° C. and these conditions were held for anadditional 2 hours. The temperature was raised to 285° C. (inapproximately 25 minutes) and the pressure was reduced to 0.3 mm of Hgover a period of 5 minutes. The stirring was reduced as the viscosityincreased, with 15 RPM being the minimum stirring used. The totalpolymerization time was varied to attain the target inherentviscosities. After the polymerization was complete, the Belmont metalbath was lowered and the polymer was allowed to cool to below its glasstransition temperature. After about 30 minutes, the flask was reimmersedin the Belmont metal bath (the temperature had been increased to 295° C.during this 30 minute wait) and the polymer mass was heated until itpulled away from the glass flask. The polymer mass was stirred at midlevel in the flask until the polymer had cooled. The polymer was removedfrom the flask and ground to pass a 3 mm screen. Variations to thisprocedure were made to produce the copolyesters described below with atargeted composition of 20 mol %.

Inherent viscosities were measured as described in the “MeasurementMethods” section above. The compositions of the polyesters weredetermined by ¹H NMR as explained before in the Measurement Methodssection. The glass transition temperatures were determined by DSC, usingthe second heat after quench at a rate of 20° C./min.

Example 7G to Example 7P

These polyesters were prepared by carrying out the ester exchange andpolycondensation reactions in separate stages. The ester exchangeexperiments were conducted in a continuous temperature rise (CTR)reactor. The CTR was a 3000 ml glass reactor equipped with a singleshaft impeller blade agitator, covered with an electric heating mantleand fitted with a heated packed reflux condenser column. The reactor wascharged with 777 g ( 4 moles) of dimethyl terephthalate, 230 g (1.6moles) of 2,2,4,4-tetramethyl-1,3,-cyclobutanediol, 460.8 g (3.2 moles)of cyclohexane dimethanol and 1.12 g of butyltin tris-2-ethylhexanoate(such that there will be 200 ppm tin metal in the final polymer). Theheating mantle was set manually to 100% output. The set points and datacollection were facilitated by a Camile process control system. Once thereactants were melted, stirring was initiated and slowly increased to250 rpm. The temperature of the reactor gradually increased with runtime. The weight of methanol collected was recorded via balance. Thereaction was stopped when methanol evolution stopped or at apre-selected lower temperature of 260° C. The oligomer was dischargedwith a nitrogen purge and cooled to room temperature. The oligomer wasfrozen with liquid nitrogen and broken into pieces small enough to beweighed into a 500 ml round bottom flask.

In the polycondensation reactions, a 500 ml round bottom flask wascharged with approximately 150 g of the oligomer prepared above. Theflask was equipped with a stainless steel stirrer and polymer head. Theglassware was set up on a half mole polymer rig and the Camile sequencewas initiated. The stirrer was positioned one full turn from the flaskbottom once the oligomer melted. The temperature/pressure/stir ratesequence controlled by the Camile software for each example is reportedin the following tables.

Camile Sequence for Example 7G and Example 7H Time Temp Vacuum StirStage (min) (° C.) (torr) (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265760 50 4 3 265 90 50 5 110 290 90 50 6 5 290 6 25 7 110 290 6 25

Camile Sequence for Example 7M to Example 7P Time Temp Vacuum Stir Stage(min) (° C.) (torr) (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265 760 50 43 265 90 50 5 110 290 90 50 6 5 290 3 25 7 110 290 3 25

Camile Sequence for Example 7J and Example 7K Time Temp Vacuum StirStage (min) (° C.) (torr) (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265760 50 4 3 265 90 50 5 110 290 90 50 6 5 290 2 25 7 110 290 2 25

Camile Sequence for Example 7I and Example 7L Time Temp Vacuum StirStage (min) (° C.) (torr) (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265760 50 4 3 265 90 50 5 110 290 90 50 6 5 290 1 25 7 110 290 1 25

The resulting polymers were recovered from the flask, chopped using ahydraulic chopper, and ground to a 6 mm screen size. Samples of eachground polymer were submitted for inherent viscosity in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.,catalyst level (Sn) by x-ray fluorescence, and color (L*, a*, b*) bytransmission spectroscopy. Polymer composition was obtained by ¹H NMR.Samples were submitted for thermal stability and melt viscosity testingusing a Rheometrics Mechanical Spectrometer (RMS-800).

The table below shows the experimental data for the polyesters of thisexample. The data shows that an increase in the level of2,2,4,4-tetramethyl-1,3-cyclobutanediol raises the glass transitiontemperature in an almost linear fashion, for a constant inherentviscosity. FIG. 3 also shows the dependence of Tg on composition andinherent viscosity. TABLE 7 Glass transition temperature as a functionof inherent viscosity and composition IV η_(o) at η_(o) at η_(o) at mol% % cis (dL/ T_(g) 260° C. 275° C. 290° C. Example TMCD TMCD g) (° C.)(Poise) (Poise) (Poise) A 20 51.4 0.72 109 11356 19503 5527 B 19.1 51.40.60 106 6891 3937 2051 C 19 53.2 0.64 107 8072 4745 2686 D 18.8 54.40.70 108 14937 8774 4610 E 17.8 52.4 0.50 103 3563 1225 883 F 17.5 51.90.75 107 21160 10877 5256 G 22.8 53.5 0.69 109 NA NA NA H 22.7 52.2 0.68108 NA NA NA I 23.4 52.4 0.73 111 NA NA NA J 23.3 52.9 0.71 111 NA NA NAK 23.3 52.4 0.74 112 NA NA NA L 23.2 52.5 0.74 112 NA NA NA M 23.1 52.50.71 111 NA NA NA N 22.8 52.4 0.73 112 NA NA NA O 22.7 53 0.69 112 NA NANA P 22.7 52 0.70 111 NA NA NANA = Not available

Example 8

This example illustrates the effect of the amount of2,2,4,4-tetramethyl-1,3-cyclobutanediol used for the preparation of thepolyesters of the invention on the glass transition temperature of thepolyesters. Polyesters prepared in this example fall comprise more than25 to less than 40 mol % of 2,2,4,4-tetramethyl-1,3-cyclobutanediolresidues.

Dimethyl terephthalate, 1,4-cyclohexanedimethanol, and2,2,4,4-tetramethyl-1,3-cyclobutanediol were weighed into a 500-mlsingle neck round bottom flask. NMR analysis on the2,2,4,4-tetramethyl-1,3-cyclobutanediol starting material showed acis/trans ratio of 53/47. The polyesters of this example were preparedwith a 1.2/1 glycol/acid ratio with the entire excess coming from the2,2,4,4-tetramethyl-1,3-cyclobutanediol. Enough dibutyltin oxidecatalyst was added to give 300 ppm tin in the final polymer. The flaskwas under a 0.2 SCFC nitrogen purge with vacuum reduction capability.The flask was immersed in a Belmont metal bath at 200° C. and stirred at200 RPM after the reactants had melted. After about 2.5 hours, thetemperature was raised to 210° C. and these conditions were held for anadditional 2 hours. The temperature was raised to 285° C. (inapproximately 25 minutes) and the pressure was reduced to 0.3 mm of Hgover a period of 5 minutes. The stirring was reduced as the viscosityincreased, with 15 RPM being the minimum stirring used. The totalpolymerization time was varied to attain the target inherentviscosities. After the polymerization was complete, the Belmont metalbath was lowered and the polymer was allowed to cool to below its glasstransition temperature. After about 30 minutes, the flask was reimmersedin the Belmont metal bath (the temperature had been increased to 295° C.during this 30 minute wait) and the polymer mass was heated until itpulled away from the glass flask. The polymer mass was stirred at midlevel in the flask until the polymer had cooled. The polymer was removedfrom the flask and ground to pass a 3 mm screen. Variations to thisprocedure were made to produce the copolyesters described below with atargeted composition of 32 mol %.

Inherent viscosities were measured as described in the “MeasurementMethods” section above. The compositions of the polyesters weredetermined by ¹H NMR as explained before in the Measurement Methodssection. The glass transition temperatures were determined by DSC, usingthe second heat after quench at a rate of 20° C./min.

The table below shows the experimental data for the polyesters of thisexample. FIG. 3 also shows the dependence of Tg on composition andinherent viscosity. The data shows that an increase in the level of2,2,4,4-tetramethyl-1,3-cyclobutanediol raises the glass transitiontemperature in an almost linear fashion, for a constant inherentviscosity. TABLE 8 Glass transition temperature as a function ofinherent viscosity and composition IV η_(o) at η_(o) at η_(o) at mol % %cis (dL/ T_(g) 260° C. 275° C. 290° C. Example TMCD TMCD g) (° C.)(Poise) (Poise) (Poise) A 32.2 51.9 0.71 118 29685 16074 8522 B 31.651.5 0.55 112 5195 2899 2088 C 31.5 50.8 0.62 112 8192 4133 2258 D 30.750.7 0.54 111 4345 2434 1154 E 30.3 51.2 0.61 111 7929 4383 2261 F 30.051.4 0.74 117 31476 17864 8630 G 29.0 51.5 0.67 112 16322 8787 4355 H31.1 51.4 0.35 102 NA NA NANA = Not available

Example 9

This example illustrates the effect of the amount of2,2,4,4-tetramethyl-1,3-cyclobutanediol used for the preparation of thepolyesters of the invention on the glass transition temperature of thepolyesters. Polyesters prepared in this example comprise2,2,4,4-tetramethyl-1,3-cyclobutanediol residues in an amount of 40 mol% or greater.

Examples A to AC

These polyesters were prepared by carrying out the ester exchange andpolycondensation reactions in separate stages. The ester exchangeexperiments were conducted in a continuous temperature rise (CTR)reactor. The CTR was a 3000 ml glass reactor equipped with a singleshaft impeller blade agitator, covered with an electric heating mantleand fitted with a heated packed reflux condenser column. The reactor wascharged with 777 g of dimethyl terephthalate, 375 g of2,2,4,4-tetramethyl-1,3,-cyclobutanediol, 317 g of cyclohexanedimethanol and 1.12 g of butyltin tris-2-ethylhexanoate (such that therewill be 200 ppm tin metal in the final polymer). The heating mantle wasset manually to 100% output. The set points and data collection werefacilitated by a Camile process control system. Once the reactants weremelted, stirring was initiated and slowly increased to 250 rpm. Thetemperature of the reactor gradully increased with run time. The weightof methanol collected was recorded via balance. The reaction was stoppedwhen methanol evolution stopped or at a pre-selected lower temperatureof 260° C. The oligomer was discharged with a nitrogen purge and cooledto room temperature. The oligomer was frozen with liquid nitrogen andbroken into pieces small enough to be weighed into a 500 ml round bottomflask.

In the polycondensation reactions, a 500 ml round bottom flask wascharged with 150 g of the oligomer prepared above. The flask wasequipped with a stainless steel stirrer and polymer head. The glasswarewas set up on a half mole polymer rig and the Camile sequence wasinitiated. The stirrer was positioned one full turn from the flaskbottom once the oligomer melted. The temperature/pressure/stir ratesequence controlled by the Camile software for these examples isreported in the following table, unless otherwise specified below.

Camile Sequence for Polycondensation Reactions Vacuum Stage Time (min)Temp (° C.) (torr) Stir (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265 76050 4 3 265 90 50 5 110 290 90 50 6 5 290 6 25 7 110 290 6 25

Camile Sequence for Examples A, C, R, Y, AB, AC Vacuum Stage Time (min)Temp (° C.) (torr) Stir (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265 76050 4 3 265 90 50 5 110 290 90 50 6 5 290 6 25 7 110 290 6 25

For Examples B, D, F, the same sequence in the preceding table was used,except the time was 80 min in Stage 7. For Examples G and J, the samesequence in the preceding table was used, except the time was 50 min inStage 7. For Example L, the same sequence in the preceding table wasused, except the time was 140 min in Stage 7.

Camile Sequence for Example E Vacuum Stage Time (min) Temp (° C.) (torr)Stir (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265 760 50 4 3 265 90 50 5110 300 90 50 6 5 300 7 25 7 110 300 7 25

For Example I, the same sequence in the preceding table was used, exceptthe vacuum was 8 torr in Stages 6 and 7. For Example O, the samesequence in the preceding table was used, except the vacuum was 6 torrin Stages 6 and 7. For Example P, the same sequence in the precedingtable was used, except the vacuum was 4 torr in Stages 6 and 7. ForExample Q, the same sequence in the preceding table was used, except thevacuum was 5 torr in Stages 6 and 7.

Camile Sequence for Example H Vacuum Stage Time (min) Temp (° C.) (torr)Stir (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265 760 50 4 3 265 90 50 5110 280 90 50 6 5 280 5 25 7 110 280 5 25

For Example U and AA, the same sequence in the preceding table was used,except the vacuum was 6 torr in Stages 6 and 7. For Example V and X, thesame sequence in the preceding table was used, except the vacuum was 6torr and stir rate was 15 rpm in Stages 6 and 7. For Example Z, the samesequence in the preceding table was used, except the stir rate was 15rpm in Stages 6 d 7.

Camile Sequence for Example K Vacuum Stage Time (min) Temp (° C.) (torr)Stir (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265 760 50 4 3 265 90 50 5110 300 90 50 6 5 300 6 15 7 110 300 6 15

For Example M, the same sequence in the preceding table was used, exceptthe vacuum was 8 torr in Stages 6 and 7. For Example N, the samesequence in the preceding table was used, except the vacuum was 7 torrin Stages 6 and 7.

Camile Sequence for Examples S and T Vacuum Stage Time (min) Temp (° C.)(torr) Stir (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265 760 50 4 5 290 625 5 110 290 6 25

The resulting polymers were recovered from the flask, chopped using ahydraulic chopper, and ground to a 6 mm screen size. Samples of eachground polymer were submitted for inherent viscosity in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.,catalyst level (Sn) by x-ray fluorescence, and color (L*, a*, b*) bytransmission spectroscopy. Polymer composition was obtained by 1H NMR.Samples were submitted for thermal stability and melt viscosity testingusing a Rheometrics Mechanical Spectrometer (RMS-800).

Examples AD to AK and AT

The polyesters of these examples were prepared as described above forExamples A to AC, except that the target tin amount in the final polymerwas 150 ppm for examples AD to AK and AT. The following tables describedthe temperature/pressure/stir rate sequences controlled by the Camilesoftware for these examples.

Camile Sequence for Examples AD, AF, and AH Vacuum Stage Time (min) Temp(° C.) (torr) Stir (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265 760 50 43 265 400 50 5 110 290 400 50 6 5 290 8 50 7 110 295 8 50

For Example AD, the stirrer was turned to 25 rpm with 95 min left inStage 7.

Camile Sequence for Example AE Vacuum Stage Time (min) Temp (° C.)(torr) Stir (rpm) 1 10 245 760 0 2 5 245 760 50 3 30 283 760 50 4 3 283175 50 5 5 283 5 50 6 5 283 1.2 50 7 71 285 1.2 50

For Example AK, the same sequence in the preceding table was used,except the time was 75 min in Stage 7.

Camile Sequence for Example AG Vacuum Stage Time (min) Temp (° C.)(torr) Stir (rpm) 1 10 245 760 0 2 5 245 760 50 3 30 285 760 50 4 3 285175 50 5 5 285 5 50 6 5 285 4 50 7 220 290 4 50

Camile Sequence for Example AI Vacuum Stage Time (min) Temp (° C.)(torr) Stir (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265 760 50 4 3 26590 50 5 110 285 90 50 6 5 285 6 50 7 70 290 6 50

Camile Sequence for Example AJ Vacuum Stage Time (min) Temp (° C.)(torr) Stir (rpm) 1 5 245 760 0 2 5 245 760 50 3 30 265 760 50 4 3 26590 50 5 110 290 90 50 6 5 290 6 25 7 110 295 6 25

Examples AL to AS

Dimethyl terephthalate, 1,4-cyclohexanedimethanol, and2,2,4,4-tetramethyl-1,3-cyclobutanediol were weighed into a 500-mlsingle neck round bottom flask. The polyesters of this example wereprepared with a 1.2/1 glycol/acid ratio with the entire excess comingfrom the 2,2,4,4-tetramethyl-1,3-cyclobutanediol. Enough dibutyltinoxide catalyst was added to give 300 ppm tin in the final polymer. Theflask was under a 0.2 SCFC nitrogen purge with vacuum reductioncapability. The flask was immersed in a Belmont metal bath at 200° C.and stirred at 200 RPM after the reactants had melted. After about 2.5hours, the temperature was raised to 210° C. and these conditions wereheld for an additional 2 hours. The temperature was raised to 285° C.(in approximately 25 minutes) and the pressure was reduced to 0.3 mm ofHg over a period of 5 minutes. The stirring was reduced as the viscosityincreased, with 15 RPM being the minimum stirring used. The totalpolymerization time was varied to attain the target inherentviscosities. After the polymerization was complete, the Belmont metalbath was lowered and the polymer was allowed to cool to below its glasstransition temperature. After about 30 minutes, the flask was reimmersedin the Belmont metal bath (the temperature had been increased to 295° C.during this 30 minute wait) and the polymer mass was heated until itpulled away from the glass flask. The polymer mass was stirred at midlevel in the flask until the polymer had cooled. The polymer was removedfrom the flask and ground to pass a 3 mm screen. Variations to thisprocedure were made to produce the copolyesters described below with atargeted composition of 45 mol %.

Inherent viscosities were measured as described in the “MeasurementMethods” section above. The compositions of the polyesters weredetermined by ¹H NMR as explained before in the Measurement Methodssection. The glass transition temperatures were determined by DSC, usingthe second heat after quench at a rate of 20° C./min.

The table below shows the experimental data for the polyesters of thisexample. The data shows that an increase in the level of2,2,4,4-tetramethyl-1,3-cyclobutanediol raises the glass transitiontemperature in an almost linear fashion, for a constant inherentviscosity. FIG. 3 also shows the dependence of Tg on composition andinherent viscosity. TABLE 9 Glass transition temperature as a functionof inherent viscosity and composition IV η_(o) at η_(o) at η_(o) at mol% % cis (dL/ T_(g) 260° C. 275° C. 290° C. Example TMCD TMCD g) (° C.)(Poise) (Poise) (Poise) A 43.9 72.1 0.46 131 NA NA NA B 44.2 36.4 0.49118 NA NA NA C 44 71.7 0.49 128 NA NA NA D 44.3 36.3 0.51 119 NA NA NA E46.1 46.8 0.51 125 NA NA NA F 43.6 72.1 0.52 128 NA NA NA G 43.6 72.30.54 127 NA NA NA H 46.4 46.4 0.54 127 NA NA NA I 45.7 47.1 0.55 125 NANA NA J 44.4 35.6 0.55 118 NA NA NA K 45.2 46.8 0.56 124 NA NA NA L 43.872.2 0.56 129 NA NA NA M 45.8 46.4 0.56 124 NA NA NA N 45.1 47.0 0.57125 NA NA NA O 45.2 46.8 0.57 124 NA NA NA P 45 46.7 0.57 125 NA NA NA Q45.1 47.1 0.58 127 NA NA NA R 44.7 35.4 0.59 123 NA NA NA S 46.1 46.40.60 127 NA NA NA T 45.7 46.8 0.60 129 NA NA NA U 46 46.3 0.62 128 NA NANA V 45.9 46.3 0.62 128 NA NA NA X 45.8 46.1 0.63 128 NA NA NA Y 45.650.7 0.63 128 NA NA NA Z 46.2 46.8 0.65 129 NA NA NA AA 45.9 46.2 0.66128 NA NA NA AB 45.2 46.4 0.66 128 NA NA NA AC 45.1 46.5 0.68 129 NA NANA AD 46.3 52.4 0.52 NA NA NA NA AE 45.7 50.9 0.54 NA NA NA NA AF 46.352.6 0.56 NA NA NA NA AG 46 50.6 0.56 NA NA NA NA AH 46.5 51.8 0.57 NANA NA NA AI 45.6 51.2 0.58 NA NA NA NA AJ 46 51.9 0.58 NA NA NA NA AK45.5 51.2 0.59 NA NA NA NA AL 45.8 50.1 0.624 125 NA NA 7696 AM 45.749.4 0.619 128 NA NA 7209 AN 46.2 49.3 0.548 124 NA NA 2348 AP 45.9 49.50.72 128 76600 40260 19110 AQ 46.0 50 0.71 131 68310 32480 17817 AR 46.149.6 0.383 117 NA NA 387 AS 45.6 50.5 0.325 108 NA NA NA AT 47.2 NA 0.48NA NA NA NANA = Not available

Example 10

This example illustrates the effect of the predominance of the type of2,2,4,4-tetramethyl-1,3-cyclobutanediol isomer (cis or trans) on theglass transition temperature of the polyester.

Dimethyl terephthalate, 1,4-cyclohexanedimethanol, and2,2,4,4-tetramethyl-1,3-cyclobutanediol were weighed into a 500-mlsingle neck round bottom flask. The polyesters of this example wereprepared with a 1.2/1 glycol/acid ratio with the entire excess comingfrom the 2,2,4,4-tetramethyl-1,3-cyclobutanediol. Enough dibutyltinoxide catalyst was added to give 300 ppm tin in the final polymer. Theflask was under a 0.2 SCFC nitrogen purge with vacuum reductioncapability. The flask was immersed in a Belmont metal bath at 200° C.and stirred at 200 RPM after the reactants had melted. After about 2.5hours, the temperature was raised to 210° C. and these conditions wereheld for an additional 2 hours. The temperature was raised to 285° C.(in approximately 25 minutes) and the pressure was reduced to 0.3 mm ofHg over a period of 5 minutes. The stirring was reduced as the viscosityincreased, with 15 RPM being the minimum stirring used. The totalpolymerization time was varied to attain the target inherentviscosities. After the polymerization was complete, the Belmont metalbath was lowered and the polymer was allowed to cool to below its glasstransition temperature. After about 30 minutes, the flask was reimmersedin the Belmont metal bath (the temperature had been increased to 295° C.during this 30 minute wait) and the polymer mass was heated until itpulled away from the glass flask. The polymer mass was stirred at midlevel in the flask until the polymer had cooled. The polymer was removedfrom the flask and ground to pass a 3 mm screen. Variations to thisprocedure were made to produce the copolyesters described below with atargeted composition of 45 mol %.

Inherent viscosities were measured as described in the “MeasurementMethods” section above. The compositions of the polyesters weredetermined by ¹H NMR as explained before in the Measurement Methodssection. The glass transition temperatures were determined by DSC, usingthe second heat after quench at a rate of 20° C./min.

The table below shows the experimental data for the polyesters of thisExample. The data shows that cis 2,2,4,4-tetramethyl-1,3-cyclobutanediolis approximately twice as effective as trans2,2,4,4-tetramethyl-1,3-cyclobutanediol at increasing the glasstransition temperature for a constant inherent viscosity. TABLE 10Effect of 2,2,4,4-tetramethyl-1,3-cyclobutanediol cis/trans compositionon T_(g) IV η_(o) at η_(o) at η_(o) at mol % (dL/ T_(g) 260° C. 275° C.290° C. % cis Example TMCD g) (° C.) (Poise) (Poise) (Poise) TMCD A 45.80.71 119 N.A. N.A. N.A. 4.1 B 43.2 0.72 122 N.A. N.A. N.A. 22.0 C 46.80.57 119 26306 16941 6601 22.8 D 43.0 0.67 125 55060 36747 14410 23.8 E43.8 0.72 127 101000 62750 25330 24.5 F 45.9 0.533 119 11474 6864 280626.4 G 45.0 0.35 107 N.A. N.A. N.A. 27.2 H 41.2 0.38 106 1214 757 N.A.29.0 I 44.7 0.59 123 N.A. N.A. N.A. 35.4 J 44.4 0.55 118 N.A. N.A. N.A.35.6 K 44.3 0.51 119 N.A. N.A. N.A. 36.3 L 44.0 0.49 128 N.A. N.A. N.A.71.7 M 43.6 0.52 128 N.A. N.A. N.A. 72.1 N 43.6 0.54 127 N.A. N.A. N.A.72.3 O 41.5 0.58 133 15419 10253 4252 88.7 P 43.8 0.57 135 16219 102264235 89.6 Q 41.0 0.33 120 521 351 2261 90.4 R 43.0 0.56 134 N.A. N.A.N.A. 90.6 S 43.0 0.49 132 7055 4620 2120 90.6 T 43.1 0.55 134 12970 84433531 91.2 U 45.9 0.52 137 N.A. N.A. N.A. 98.1NA = not available

Example 11

This example illustrates the preparation of a copolyester containing 100mol % dimethyl terephthalate residues, 55 mol %1,4-cyclohexanedimethanol residues, and 45 mol %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.

A mixture of 97.10 g (0.5 mol) dimethyl terephthalate, 52.46 g (0.36mol) 1,4-cyclohexanedimethanol, 34.07 g (0.24 mol)2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 0.0863 g (300 ppm) dibutyltin oxide was placed in a 500-milliliter flask equipped with an inletfor nitrogen, a metal stirrer, and a short distillation column. Theflask was placed in a Wood's metal bath already heated to 200° C. Thecontents of the flask were heated at 200° C. for 1 hour and then thetemperature was increased to 210° C. The reaction mixture was held at210° C. for 2 hours and then heated up to 290° C. in 30 minutes. Once at290° C., a vacuum of 0.01 psig was gradually applied over the next 3 to5 minutes. Full vacuum (0.01 psig) was maintained for a total time ofabout 45 minutes to remove excess unreacted diols. A high meltviscosity, visually clear and colorless polymer was obtained with aglass transition temperature of 125° C. and an inherent viscosity of0.64 dl/g.

Example 12 Comparative Example

This example illustrates that a polyester based on 100%2,2,4,4-tetramethyl-1,3-cyclobutanediol has a slow crystallizationhalf-time.

A polyester based solely on terephthalic acid and2,2,4,4-tetramethyl-1,3-cyclobutanediol was prepared in a method similarto the method described in Example 1A with the properties shown on Table11. This polyester was made with 300 ppm dibutyl tin oxide. Thetrans/cis ratio of the 2,2,4,4-tetramethyl-1,3-cyclobutanediol was65/35.

Films were pressed from the ground polymer at 320° C. Crystallizationhalf-time measurements from the melt were made at temperatures from 220to 250° C. at 10° C. increments and are reported in Table 11. Thefastest crystallization half-time for the sample was taken as theminimum value of crystallization half-time as a function of temperature.The fastest crystallization half-time of this polyester is around 1300minutes. This value contrasts with the fact that the polyester (PCT)based solely on terephthalic acid and 1,4-cyclohexanedimethanol (nocomonomer modification) has an extremely short crystallization half-time(<1 min) as shown in FIG. 1. TABLE 11 Crystallization Half-times (min)at at at at Comonomer IV T_(g) T_(max) 220° C. 230° C. 240° C. 250° C.(mol %) (dl/g) (° C.) (° C.) (min) (min) (min) (min) 100 mol %F 0.63170.0 330 3291 3066 1303 1888where:F is 2,2,4,4-Tetramethyl-1,3-cyclobutanediol (65/35 Trans/Cis)

Example 13

Sheets comprising a polyester that had been prepared with a targetcomposition of 100 mole % terephthalic acid residues, 80 mole %1,4-cyclohexanedimethanol residues, and 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues were produced using a3.5 inch single screw extruder. A sheet was extruded continuously,gauged to a thickness of 177 mil and then various sheets were sheared tosize. Inherent viscosity and glass transition temperature were measuredon one sheet. The sheet inherent viscosity was measured to be 0.69 dl/g.The glass transition temperature of the sheet was measured to be 106° C.Sheets were then conditioned at 50% relative humidity and 60° C. for 2weeks. Sheets were subsequently thermoformed into a female mold having adraw ratio of 2.5:1 using a Brown thermoforming machine. Thethermoforming oven heaters were set to 70/60/60% output using top heatonly. Sheets were left in the oven for various amounts of time in orderto determine the effect of sheet temperature on the part quality asshown in the table below. Part quality was determined by measuring thevolume of the thermoformed part, calculating the draw, and visuallyinspecting the thermoformed part. The draw was calculated as the partvolume divided by the maximum part volume achieved in this set ofexperiments (Example G). The thermoformed part was visually inspectedfor any blisters and the degree of blistering rated as none (N), low(L), or high (H). The results below demonstrate that these thermoplasticsheets with a glass transition temperature of 106° C. can bethermoformed under the conditions shown below, as evidenced by thesesheets having at least 95% draw and no blistering, without predrying thesheets prior to thermoforming. Thermoforming Conditions Part QualitySheet Part Heat Time Temperature Volume Blisters Example (s) (° C.) (mL)Draw (%) (N, L, H) A 86 145 501 64 N B 100 150 500 63 N C 118 156 672 85N D 135 163 736 94 N E 143 166 760 97 N F 150 168 740 94 L G 159 172 787100 L

Example 14

Sheets comprising a polyester that had been prepared with a targetcomposition of 100 mole % terephthalic acid residues, 80 mole %1,4-cyclohexanedimethanol residues, and 20 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues were produced using a3.5 inch single screw. A sheet was extruded continuously, gauged to athickness of 177 mil and then various sheets were sheared to size.Inherent viscosity and glass transition temperature were measured on onesheet. The sheet inherent viscosity was measured to be 0.69 dl/g. Theglass transition temperature of the sheet was measured to be 106° C.Sheets were then conditioned at 100% relative humidity and 25° C. for 2weeks. Sheets were subsequently thermoformed into a female mold having adraw ratio of 2.5:1 using a Brown thermoforming machine. Thethermoforming oven heaters were set to 60/40/40% output using top heatonly. Sheets were left in the oven for various amounts of time in orderto determine the effect of sheet temperature on the part quality asshown in the table below. Part quality was determined by measuring thevolume of the thermoformed part, calculating the draw, and visuallyinspecting the thermoformed part. The draw was calculated as the partvolume divided by the maximum part volume achieved in this set ofexperiments (Example G). The thermoformed part was visually inspectedfor any blisters and the degree of blistering rated as none (N), low(L), or high (H). The results below demonstrate that these thermoplasticsheets with a glass transition temperature of 106° C. can bethermoformed under the conditions shown below, as evidenced by theproduction of sheets having at least 95% draw and no blistering, withoutpredrying the sheets prior to thermoforming. Thermoforming ConditionsPart Quality Sheet Part Heat Time Temperature Volume Blisters Example(s) (° C.) (mL) Draw (%) (N, L, H) A 141 154 394 53 N B 163 157 606 82 NC 185 160 702 95 N D 195 161 698 95 N E 215 163 699 95 L F 230 168 70596 L G 274 174 737 100 H H 275 181 726 99 H

Example 15 Comparative Example

Sheets consisting of Kelvx 201 were produced using a 3.5 inch singlescrew extruder. Kelvx is a blend consisting of 69.85% PCTG (Eastar fromEastman Chemical Co. having 100 mole % terephthalic acid residues, 62mole % 1,4-cyclohexanedimethanol residues, and 38 mole % ethylene glycolresidues); 30% PC (bisphenol A polycarbonate); and 0.15% Weston 619(stabilizer sold by Crompton Corporation). A sheet was extrudedcontinuously, gauged to a thickness of 177 mil and then various sheetswere sheared to size. The glass transition temperature was measured onone sheet and was 100° C. Sheets were then conditioned at 50% relativehumidity and 60° C. for 2 weeks. Sheets were subsequently thermoformedinto a female mold having a draw ratio of 2.5:1 using a Brownthermoforming machine. The thermoforming oven heaters were set to70/60/60% output using top heat only. Sheets were left in the oven forvarious amounts of time in order to determine the effect of sheettemperature on the part quality as shown in the table below. Partquality was determined by measuring the volume of the thermoformed part,calculating the draw, and visually inspecting the thermoformed part. Thedraw was calculated as the part volume divided by the maximum partvolume achieved in this set of experiments (Example E). The thermoformedpart was visually inspected for any blisters and the degree ofblistering rated as none (N), low (L), or high (H). The results belowdemonstrate that these thermoplastic sheets with a glass transitiontemperature of 100° C. can be thermoformed under the conditions shownbelow, as evidenced by the production of sheets having at least 95% drawand no blistering, without predrying the sheets prior to thermoforming.Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 90 146 58275 N B 101 150 644 83 N C 171 154 763 98 N D 126 159 733 95 N E 126 159775 100 N F 141 165 757 98 N G 148 168 760 98 L

Example 16 Comparative Example

Sheets consisting of Kelvx 201 were produced using a 3.5 inch singlescrew extruder. A sheet was extruded continuously, gauged to a thicknessof 177 mil and then various sheets were sheared to size. The glasstransition temperature was measured on one sheet and was 100° C. Sheetswere then conditioned at 100% relative humidity and 25° C. for 2 weeks.Sheets were subsequently thermoformed into a female mold having a drawratio of 2.5:1 using a Brown thermoforming machine. The thermoformingoven heaters were set to 60/40/40% output using top heat only. Sheetswere left in the oven for various amounts of time in order to determinethe effect of sheet temperature on the part quality as shown in thetable below. Part quality was determined by measuring the volume of thethermoformed part, calculating the draw, and visually inspecting thethermoformed part. The draw was calculated as the part volume divided bythe maximum part volume achieved in this set of experiments (Example H).The thermoformed part was visually inspected for any blisters and thedegree of blistering rated as none (N), low (L), or high (H). Theresults below demonstrate that these thermoplastic sheets with a glasstransition temperature of 100° C. can be thermoformed under theconditions shown below, as evidenced by the production of sheets havinggreater than 95% draw and no blistering, without predrying the sheetsprior to thermoforming. Thermoforming Conditions Part Quality Sheet PartHeat Time Temperature Volume Blisters Example (s) (° C.) (mL) Draw (%)(N, L, H) A 110 143 185 25 N B 145 149 529 70 N C 170 154 721 95 N D 175156 725 96 N E 185 157 728 96 N F 206 160 743 98 L G 253 NR 742 98 H H261 166 756 100 HNR = Not recorded

Example 17 Comparative Example

Sheets consisting of PCTG 25976 (100 mole % terephthalic acid residues,62 mole % 1,4-cyclohexanedimethanol residues, and 38 mole % ethyleneglycol residues) were produced using a 3.5 inch single screw extruder. Asheet was extruded continuously, gauged to a thickness of 118 mil andthen various sheets were sheared to size. The glass transitiontemperature was measured on one sheet and was 87° C. Sheets were thenconditioned at 50% relative humidity and 60° C. for 4 weeks. Themoisture level was measured to be 0.17 wt %. Sheets were subsequentlythermoformed into a female mold having a draw ratio of 2.5:1 using aBrown thermoforming machine. The thermoforming oven heaters were set to70/60/60% output using top heat only. Sheets were left in the oven forvarious amounts of time in order to determine the effect of sheettemperature on the part quality as shown in the table below. Partquality was determined by measuring the volume of the thermoformed part,calculating the draw, and visually inspecting the thermoformed part. Thedraw was calculated as the part volume divided by the maximum partvolume achieved in this set of experiments (Example A). The thermoformedpart was visually inspected for any blisters and the degree ofblistering rated as none (N), low (L), or high (H). The results belowdemonstrate that these thermoplastic sheets with a glass transitiontemperature of 87° C. can be thermoformed under the conditions shownbelow, as evidenced by the production of sheets having greater than 95%draw and no blistering, without predrying the sheets prior tothermoforming. Thermoforming Conditions Part Quality Sheet Part HeatTime Temperature Volume Blisters Example (s) (° C.) (mL) Draw (%) (N, L,H) A 102 183 816 100 N B 92 171 811 99 N C 77 160 805 99 N D 68 149 80499 N E 55 143 790 97 N F 57 138 697 85 N

Example 18 Comparative Example

A miscible blend consisting of 20 wt % Teijin L-1250 polycarbonate (abisphenol-A polycarbonate), 79.85 wt % PCTG 25976, and 0.15 wt % Weston619 was produced using a 1.25 inch single screw extruder. Sheetsconsisting of the blend were then produced using a 3.5 inch single screwextruder. A sheet was extruded continuously, gauged to a thickness of118 mil and then various sheets were sheared to size. The glasstransition temperature was measured on one sheet and was 94° C. Sheetswere then conditioned at 50% relative humidity and 60° C. for 4 weeks.The moisture level was measured to be 0.25 wt %. Sheets weresubsequently thermoformed into a female mold having a draw ratio of2.5:1 using a Brown thermoforming machine. The thermoforming ovenheaters were set to 70/60/60% output using top heat only. Sheets wereleft in the oven for various amounts of time in order to determine theeffect of sheet temperature on the part quality as shown in the tablebelow. Part quality was determined by measuring the volume of thethermoformed part, calculating the draw, and visually inspecting thethermoformed part. The draw was calculated as the part volume divided bythe maximum part volume achieved in this set of experiments (Example A).The thermoformed part was visually inspected for any blisters and thedegree of blistering rated as none (N), low (L), or high (H). Theresults below demonstrate that these thermoplastic sheets with a glasstransition temperature of 94° C. can be thermoformed under theconditions shown below, as evidenced by the production of sheets havinggreater than 95% draw and no blistering, without predrying the sheetsprior to thermoforming. Thermoforming Conditions Part Quality Sheet PartHeat Time Temperature Volume Blisters Example (s) (° C.) (mL) Draw (%)(N, L, H) A 92 184 844 100 H B 86 171 838 99 N C 73 160 834 99 N D 58143 787 93 N E 55 143 665 79 N

Example 19 Comparative Example

A miscible blend consisting of 30 wt % Teijin L-1250 polycarbonate,69.85 wt % PCTG 25976, and 0.15 wt % Weston 619 was produced using a1.25 inch single screw extruder. Sheets consisting of the blend werethen produced using a 3.5 inch single screw extruder. A sheet wasextruded continuously, gauged to a thickness of 118 mil and then varioussheets were sheared to size. The glass transition temperature wasmeasured on one sheet and was 99° C. Sheets were then conditioned at 50%relative humidity and 60° C. for 4 weeks. The moisture level wasmeasured to be 0.25 wt %. Sheets were subsequently thermoformed into afemale mold having a draw ratio of 2.5:1 using a Brown thermoformingmachine. The thermoforming oven heaters were set to 70/60/60% outputusing top heat only. Sheets were left in the oven for various amounts oftime in order to determine the effect of sheet temperature on the partquality as shown in the table below. Part quality was determined bymeasuring the volume of the thermoformed part, calculating the draw, andvisually inspecting the thermoformed part. The draw was calculated asthe part volume divided by the maximum part volume achieved in this setof experiments (Example A). The thermoformed part was visually inspectedfor any blisters and the degree of blistering rated as none (N), low(L), or high (H). The results below demonstrate that these thermoplasticsheets with a glass transition temperature of 99° C. can be thermoformedunder the conditions shown below, as evidenced by the production ofsheets having greater than 95% draw and no blistering, without predryingthe sheets prior to thermoforming. Thermoforming Conditions Part QualitySheet Part Heat Time Temperature Volume Blisters Example (s) (° C.) (mL)Draw (%) (N, L, H) A 128 194 854 100 H B 98 182 831 97 L C 79 160 821 96N D 71 149 819 96 N E 55 145 785 92 N F 46 143 0 0 NA G 36 132 0 0 NANA = not applicable.A value of zero indicates that the sheet was not formed because it didnot pull into the mold (likely because it was too cold).

Example 20 Comparative Example

A miscible blend consisting of 40 wt % Teijin L-1250 polycarbonate,59.85 wt % PCTG 25976, and 0.15 wt % Weston 619 was produced using a1.25 inch single screw extruder. Sheets consisting of the blend werethen produced using a 3.5 inch single screw extruder. A sheet wasextruded continuously, gauged to a thickness of 118 mil and then varioussheets were sheared to size. The glass transition temperature wasmeasured on one sheet and was 105° C. Sheets were then conditioned at50% relative humidity and 60° C. for 4 weeks. The moisture level wasmeasured to be 0.265 wt %. Sheets were subsequently thermoformed into afemale mold having a draw ratio of 2.5:1 using a Brown thermoformingmachine. The thermoforming oven heaters were set to 70/60/60% outputusing top heat only. Sheets were left in the oven for various amounts oftime in order to determine the effect of sheet temperature on the partquality as shown in the table below. Part quality was determined bymeasuring the volume of the thermoformed part, calculating the draw, andvisually inspecting the thermoformed part. The draw was calculated asthe part volume divided by the maximum part volume achieved in this setof experiments (Examples 8A to 8E). The thermoformed part was visuallyinspected for any blisters and the degree of blistering rated as none(N), low (L), or high (H). The results below demonstrate that thesethermoplastic sheets with a glass transition temperature of 105° C. canbe thermoformed under the conditions shown below, as evidenced by theproduction of sheets having greater than 95% draw and no blistering,without predrying the sheets prior to thermoforming. ThermoformingConditions Part Quality Sheet Part Heat Time Temperature Volume BlistersExample (s) (° C.) (mL) Draw (%) (N, L, H) A 111 191 828 100 H B 104 182828 100 H C 99 179 827 100 N D 97 177 827 100 N E 78 160 826 100 N F 68149 759 92 N G 65 143 606 73 N

Example 21 Comparative Example

A miscible blend consisting of 50 wt % Teijin L-1250 polycarbonate,49.85 wt % PCTG 25976, and 0.15 wt % Weston 619 was produced using a1.25 inch single screw extruder. A sheet was extruded continuously,gauged to a thickness of 118 mil and then various sheets were sheared tosize. The glass transition temperature was measured on one sheet and was111° C. Sheets were then conditioned at 50% relative humidity and 60° C.for 4 weeks. The moisture level was measured to be 0.225 wt %. Sheetswere subsequently thermoformed into a female mold having a draw ratio of2.5:1 using a Brown thermoforming machine. The thermoforming ovenheaters were set to 70/60/60% output using top heat only. Sheets wereleft in the oven for various amounts of time in order to determine theeffect of sheet temperature on the part quality as shown in the tablebelow. Part quality was determined by measuring the volume of thethermoformed part, calculating the draw, and visually inspecting thethermoformed part. The draw was calculated as the part volume divided bythe maximum part volume achieved in this set of experiments (Examples Ato D). The thermoformed part was visually inspected for any blisters andthe degree of blistering rated as none (N), low (L), or high (H). Theresults below demonstrate that these thermoplastic sheets with a glasstransition temperature of 111° C. can be thermoformed under theconditions shown below, as evidenced by the production of sheets havinggreater than 95% draw and no blistering, without predrying the sheetsprior to thermoforming. Thermoforming Conditions Part Quality Sheet PartHeat Time Temperature Volume Blisters Example (s) (° C.) (mL) Draw (%)(N, L, H) A 118 192 815 100 H B 99 182 815 100 H C 97 177 814 100 L D 87171 813 100 N E 80 160 802 98 N F 64 154 739 91 N G 60 149 0 0 NANA = not applicable.A value of zero indicates that the sheet was not formed because it didnot pull into the mold (likely because it was too cold).

Example 22 Comparative Example

A miscible blend consisting of 60 wt % Teijin L-1250 polycarbonate,39.85 wt % PCTG 25976, and 0.15 wt % Weston 619 was produced using a1.25 inch single screw extruder. Sheets consisting of the blend werethen produced using a 3.5 inch single screw extruder. A sheet wasextruded continuously, gauged to a thickness of 118 mil and then varioussheets were sheared to size. The glass transition temperature wasmeasured on one sheet and was 117° C. Sheets were then conditioned at50% relative humidity and 60° C. for 4 weeks. The moisture level wasmeasured to be 0.215 wt %. Sheets were subsequently thermoformed into afemale mold having a draw ratio of 2.5:1 using a Brown thermoformingmachine. The thermoforming oven heaters were set to 70/60/60% outputusing top heat only. Sheets were left in the oven for various amounts oftime in order to determine the effect of sheet temperature on the partquality as shown in the table below. Part quality was determined bymeasuring the volume of the thermoformed part, calculating the draw, andvisually inspecting the thermoformed part. The draw was calculated asthe part volume divided by the maximum part volume achieved in this setof experiments (Example A). The thermoformed part was visually inspectedfor any blisters and the degree of blistering rated as none (N), low(L), or high (H). The results below demonstrate that these thermoplasticsheets with a glass transition temperature of 117° C. cannot bethermoformed under the conditions shown below, as evidenced by theinability to produce sheets having greater than 95% draw and noblistering, without predrying the sheets prior to thermoforming.Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 114 196 813100 H B 100 182 804 99 H C 99 177 801 98 L D 92 171 784 96 L E 82 168727 89 L F 87 166 597 73 N

Example 23 Comparative Example

A miscible blend consisting of 65 wt % Teijin L-1250 polycarbonate,34.85 wt % PCTG 25976, and 0.15 wt % Weston 619 was produced using a1.25 inch single screw extruder. Sheets consisting of the blend werethen produced using a 3.5 inch single screw extruder. A sheet wasextruded continuously, gauged to a thickness of 118 mil and then varioussheets were sheared to size. The glass transition temperature wasmeasured on one sheet and was 120° C. Sheets were then conditioned at50% relative humidity and 60° C. for 4 weeks. The moisture level wasmeasured to be 0.23 wt %. Sheets were subsequently thermoformed into afemale mold having a draw ratio of 2.5:1 using a Brown thermoformingmachine. The thermoforming oven heaters were set to 70/60/60% outputusing top heat only. Sheets were left in the oven for various amounts oftime in order to determine the effect of sheet temperature on the partquality as shown in the table below. Part quality was determined bymeasuring the volume of the thermoformed part, calculating the draw, andvisually inspecting the thermoformed part. The draw was calculated asthe part volume divided by the maximum part volume achieved in this setof experiments (Example A). The thermoformed part was visually inspectedfor any blisters and the degree of blistering rated as none (N), low(L), or high (H). The results below demonstrate that these thermoplasticsheets with a glass transition temperature of 120° C. cannot bethermoformed under the conditions shown below, as evidenced by theinability to produce sheets having greater than 95% draw and noblistering, without predrying the sheets prior to thermoforming.Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 120 197 825100 H B 101 177 820 99 H C 95 174 781 95 L D 85 171 727 88 L E 83 166558 68 L

Example 24 Comparative Example

A miscible blend consisting of 70 wt % Teijin L-1250 polycarbonate,29.85 wt % PCTG 25976, and 0.15 wt % Weston 619 was produced using a1.25 inch single screw extruder. Sheets consisting of the blend werethen produced using a 3.5 inch single screw extruder. A sheet wasextruded continuously, gauged to a thickness of 118 mil and then varioussheets were sheared to size. The glass transition temperature wasmeasured on one sheet and was 123° C. Sheets were then conditioned at50% relative humidity and 60° C. for 4 weeks. The moisture level wasmeasured to be 0.205 wt %. Sheets were subsequently thermoformed into afemale mold having a draw ratio of 2.5:1 using a Brown thermoformingmachine. The thermoforming oven heaters were set to 70/60/60% outputusing top heat only. Sheets were left in the oven for various amounts oftime in order to determine the effect of sheet temperature on the partquality as shown in the table below. Part quality was determined bymeasuring the volume of the thermoformed part, calculating the draw, andvisually inspecting the thermoformed part. The draw was calculated asthe part volume divided by the maximum part volume achieved in this setof experiments (Examples A and B). The thermoformed part was visuallyinspected for any blisters and the degree of blistering rated as none(N), low (L), or high (H). The results below demonstrate that thesethermoplastic sheets with a glass transition temperature of 123° C.cannot be thermoformed under the conditions shown below, as evidenced bythe inability to produce sheets having greater than 95% draw and noblistering, without predrying the sheets prior to thermoforming.Thermoforming Conditions Part Quality Sheet Part Heat Time TemperatureVolume Blisters Example (s) (° C.) (mL) Draw (%) (N, L, H) A 126 198 826100 H B 111 188 822 100 H C 97 177 787 95 L D 74 166 161 19 L E 58 154 00 NA F 48 149 0 0 NANA = not applicable.A value of zero indicates that the sheet was not formed because it didnot pull into the mold (likely because it was too cold).

Example 25 Comparative Example

Sheets consisting of Teijin L-1250 polycarbonate were produced using a3.5 inch single screw extruder. A sheet was extruded continuously,gauged to a thickness of 118 mil and then various sheets were sheared tosize. The glass transition temperature was measured on one sheet and was149° C. Sheets were then conditioned at 50% relative humidity and 60° C.for 4 weeks. The moisture level was measured to be 0.16 wt %. Sheetswere subsequently thermoformed into a female mold having a draw ratio of2.5:1 using a Brown thermoforming machine. The thermoforming ovenheaters were set to 70/60/60% output using top heat only. Sheets wereleft in the oven for various amounts of time in order to determine theeffect of sheet temperature on the part quality as shown in the tablebelow. Part quality was determined by measuring the volume of thethermoformed part, calculating the draw and visually inspecting thethermoformed part. The draw was calculated as the part volume divided bythe maximum part volume achieved in this set of experiments (Example A).The thermoformed part was visually inspected for any blisters and thedegree of blistering rated as none (N), low (L), or high (H). Theresults below demonstrate that these thermoplastic sheets with a glasstransition temperature of 149° C. cannot be thermoformed under theconditions shown below, as evidenced by the inability to produce sheetshaving greater than 95% draw and no blistering, without predrying thesheets prior to thermoforming. Thermoforming Conditions Part QualitySheet Part Heat Time Temperature Volume Blisters Example (s) (° C.) (mL)Draw (%) (N, L, H) A 152 216 820 100 H B 123 193 805 98 H C 113 191 17922 H D 106 188 0 0 H E 95 182 0 0 NA F 90 171 0 0 NANA = not applicable.A value of zero indicates that the sheet was not formed because it didnot pull into the mold (likely because it was too cold).

It can be clearly seen from a comparison of the data in the aboverelevant working examples that the polyesters of the present inventionoffer a definite advantage over the commercially available polyesterswith regard to glass transition temperature, density, slowcrystallization rate, melt viscosity, and toughness.

The invention has been described in detail with reference to theembodiments disclosed herein, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

1. An ophthalmic product comprising at least one polyester compositioncomprising at least one polyester, which comprises: (a) a dicarboxylicacid component comprising: i) 70 to 100 mole % of terephthalic acidresidues; ii) 0 to 30 mole % of aromatic dicarboxylic acid residueshaving up to 20 carbon atoms; and iii) 0 to 10 mole % of aliphaticdicarboxylic acid residues having up to 16 carbon atoms; and (b) aglycol component comprising: i) 10 to 99 mole % of2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and ii) 1 to 90 mole %of 1,4-cyclohexanedimethanol residues, wherein the total mole % of thedicarboxylic acid component is 100 mole %, the total mole % of theglycol component is 100 mole %; and wherein the inherent viscosity ofthe polyester is from 0.1 to 1.2 dL/g as determined in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.;and wherein the polyester has a Tg of from 100 to 200° C.
 2. Theophthalmic product of claim 1, wherein the inherent viscosity of thepolyester is from 0.35 to 1.2 dL/g.
 3. The ophthalmic product of claim1, wherein the inherent viscosity of the polyester is from 0.35 to 1.0dL/g.
 4. The ophthalmic product of claim 1, wherein the inherentviscosity of the polyester is from 0.35 to 0.75 dL/g.
 5. The ophthalmicproduct of claim 1, wherein the inherent viscosity of the polyester isfrom 0.40 to 0.90 dL/g.
 6. The ophthalmic product of claim 1, whereinthe inherent viscosity of the polyester is from greater than 0.42 to0.80 dL/g.
 7. The ophthalmic product of claim 1, wherein the inherentviscosity of the polyester is from 0.45 to 0.75 dL/g.
 8. The ophthalmicproduct of claim 1, wherein the inherent viscosity of the polyester isfrom 0.50 to 0.68 dL/g.
 9. The ophthalmic product of claim 1, whereinthe inherent viscosity of the polyester is from 0.60 to 0.75 dL/g. 10.The ophthalmic product of claim 1, wherein the polyester has a Tg of 100to 180° C.
 11. The ophthalmic product of claim 1, wherein the polyesterhas a Tg of 100 to 160° C.
 12. The ophthalmic product of claim 1,wherein the polyester has a Tg of 100 to 150° C.
 13. The ophthalmicproduct of claim 1, wherein the polyester has a Tg of 105 to 140° C. 14.The ophthalmic product of claim 1, wherein the polyester has a Tg of 100to 120° C.
 15. The ophthalmic product of claim 1, wherein the polyesterhas a Tg of 120 to 140° C.
 16. The ophthalmic product of claim 9,wherein the polyester has a Tg of 100 to 120° C.
 17. The ophthalmicproduct of claim 9, wherein the polyester has a Tg of 120 to 140° C. 18.The ophthalmic product of claim 1, wherein the glycol component of thepolyester comprises 25 to 70 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues and 30 to 75 mole %1,4-cyclohexanedimethanol residues.
 19. The ophthalmic product of claim1, wherein the glycol component of the polyester comprises 15 to 70 mole% 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues and 30 to 85 mole %1,4-cyclohexanedimethanol residues.
 20. The ophthalmic product of claim1, wherein the glycol component of the polyester comprises 15 to 60 mole% 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues and 40 to 85 mole %1,4-cyclohexanedimethanol residues.
 21. The ophthalmic product of claim1, wherein the glycol component of the polyester comprises 40 to 55 mole% 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues and 45 to 60 mole %1,4-cyclohexanedimethanol residues.
 22. The ophthalmic product of claim1, wherein the glycol component of the polyester comprises 20 to 40 mole% 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues and 60 to 80 mole %1,4-cyclohexanedimethanol residues.
 23. The ophthalmic product of claim17, wherein the glycol component of the polyester comprises 40 to 55mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues and 45 to 60mole % 1,4-cyclohexanedimethanol residues.
 24. The ophthalmic product ofclaim 16, wherein the glycol component of the polyester comprises 20 to40 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues and 60 to 80mole % 1,4-cyclohexanedimethanol residues.
 25. The ophthalmic product ofclaim 1, wherein the dicarboxylic acid component comprises 80 to 100mole % of terephthalic acid residues.
 26. The ophthalmic product ofclaim 1, wherein the dicarboxylic acid component comprises 90 to 100mole % of terephthalic acid residues.
 27. The ophthalmic product ofclaim 1, wherein the dicarboxylic acid component comprises 95 to 100mole % of terephthalic acid residues.
 28. The ophthalmic product ofclaim 1, wherein the polyester comprises from 0.1 to 25 mole % of1,3-propanediol residues, 1,4-butanediol residues, or a mixture thereof.29. The ophthalmic product of claim 1, wherein the polyester comprisesfrom 0.1 to 10 mole % of 1,3-propanediol residues, 1,4-butanediolresidues, or a mixture thereof.
 30. The ophthalmic product of claim 1,wherein the polyester comprises from 0.01 to 15 mole % of ethyleneglycol residues.
 31. The ophthalmic product of claim 1, wherein the2,2,4,4-tetramethyl-1,3-cyclobutanediol residues is a mixture comprisinggreater than 50 mole % of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediolresidues and less than 50 mole % oftrans-2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.
 32. Theophthalmic product of claim 1, wherein the2,2,4,4-tetramethyl-1,3-cyclobutanediol residues is a mixture comprisinggreater than 55 mole % of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediolresidues and less than 45 mole % oftrans-2,2,4,4-tetramethyl-1,3-cyclobutanediol residues.
 33. Theophthalmic product of claim 1, wherein the2,2,4,4-tetramethyl-1,3-cyclobutanediol is a mixture comprising greaterthan 50 mole % of cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol and lessthan 50 mole % of trans-2,2,4,4-tetramethyl-1,3-cyclobutanediol, andwherein the dicarboxylic acid component comprises 80 to 100 mole % ofterephthalic acid residues.
 34. The ophthalmic product of claim 1,wherein the polyester composition comprises at least one polymer chosenfrom poly(etherimides), polyphenylene oxides, poly(phenyleneoxide)/polystyrene blends, polystyrene resins, polyphenylene sulfides,polyphenylene sulfide/sulfones, poly(ester-carbonates), polycarbonates,polysulfones; polysulfone ethers, poly(ether-ketones), polyamides,polystyrene, polystyrene copolymers, styrene acrylonitrile copolymers,acrylonitrile butadiene styrene copolymers, poly(methylmethacrylate),and acrylic copolymers.
 35. The ophthalmic product of claim 1, whereinthe polyester composition comprises at least one polycarbonate.
 36. Theophthalmic product of claim 1, wherein the polyester comprises residuesat least one branching agent an amount of 0.01 to 10 weight % based onthe total weight of the polyester.
 37. The ophthalmic product of claim1, wherein the melt viscosity of the polyester is less than 30,000 poiseas measured at 1 radian/second on a rotary melt rheometer at 290° C. 38.The ophthalmic product of claim 1, wherein the polyester has acrystallization half-time of greater than 10 minutes at 170° C.
 39. Theophthalmic product of claim 1, wherein the polyester has acrystallization half-time of greater than 50 minutes at 170° C.
 40. Theophthalmic product of claim 1, wherein the polyester has acrystallization half-time of greater than 100 minutes at 170° C.
 41. Theophthalmic product of claim 1, wherein the polyester has acrystallization half-time of greater than 1,000 minutes at 170° C. 42.The ophthalmic product of claim 1, wherein the polyester has acrystallization half-time of greater than 10,000 minutes at 170° C. 43.The ophthalmic product of claim 1, wherein the polyester composition hasa density of less than 1.3 g/ml at 23° C.
 44. The ophthalmic product ofclaim 1, wherein the polyester composition comprises at least onethermal stabilizer or a reaction product thereof.
 45. The ophthalmicproduct of claim 1, wherein the yellowness index of the polyesteraccording to ASTM D-1925 is less than
 50. 46. The ophthalmic product ofclaim 1, wherein the polyester has a notched Izod impact strength of atleast 3 ft-lbs/in at 23° C. according to ASTM D256 with a 10-mil notchin a ⅛-inch thick bar.
 47. The ophthalmic product of claim 1, whereinthe polyester has a notched Izod impact strength of at least 10ft-lbs/in at 23° C. according to ASTM D256 with a 10-mil notch in a¼-inch thick bar.
 48. The ophthalmic product of claim 1, wherein thepolyester comprises the residue of at least one catalyst comprising atin compound or a reaction product thereof.
 49. The ophthalmic productof claim 1, wherein the ophthalmic product is chosen fromnonprescription eyeglass lenses, prescription eyeglass lenses, andsunglass lenses.
 50. The ophthalmic product of claim 1, wherein theophthalmic product is chosen from nonprescription eyeglass frames,prescription eyeglass frames, and sunglass frames.
 51. The ophthalmicproduct of claim 1, wherein the ophthalmic product is chosen from tintedeyeglass lenses.
 52. The ophthalmic product of claim 1, wherein theophthalmic product is chosen from hardcoated eyeglass lenses.
 53. Theophthalmic product of claim 1, wherein the ophthalmic product is chosenfrom eyeglass lenses comprising at least one polarizing film orpolarizing additive.
 54. The ophthalmic product of claim 51, wherein thetinted eyeglass lenses comprise at least one polarizing film orpolarizing additive.
 55. The ophthalmic product of claim 52, wherein thehardcoated eyeglass lenses comprise at least one polarizing film orpolarizing additive.
 56. The ophthalmic product of claim 1, wherein theophthalmic product has a refractive index ranging from 1.54 to 1.56. 57.The ophthalmic product of claim 1, wherein the ophthalmic product isformed by extrusion.
 58. The ophthalmic product of claim 1, wherein theophthalmic product is produced by compression molding.
 59. Theophthalmic product of claim 1, wherein the ophthalmic product isproduced by solution casting.
 60. The ophthalmic product of claim 1,wherein the ophthalmic product is formed by injection molding.
 61. Anophthalmic product comprising at least one polyester compositioncomprising at least one polyester, which comprises: (a) a dicarboxylicacid component comprising: i) 70 to 100 mole % of terephthalic acidresidues; ii) 0 to 30 mole % of aromatic dicarboxylic acid residueshaving up to 20 carbon atoms; and iii) 0 to 10 mole % of aliphaticdicarboxylic acid residues having up to 16 carbon atoms; and (b) aglycol component comprising: i) 15 to 70 mole % of2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and ii) 30 to 85 mole% of 1,4-cyclohexanedimethanol residues, wherein the total mole % of thedicarboxylic acid component is 100 mole %, the total mole % of theglycol component is 100 mole %; and wherein the inherent viscosity ofthe polyester is from 0.35 to 1.2 dL/g as determined in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.;and wherein the polyester has a Tg of from 100 to 160° C.
 62. Theophthalmic product of claim 61, wherein the inherent viscosity of thepolyester is from 0.35 to 0.75 dL/g.
 63. The ophthalmic product of claim61, wherein the inherent viscosity of the polyester is from 0.45 to 0.75dL/g.
 64. The ophthalmic product of claim 61, wherein the inherentviscosity of the polyester is from 0.50 to 0.68 dL/g.
 65. The ophthalmicproduct of claim 61, wherein the inherent viscosity of the polyester isfrom 0.60 to 0.75 dL/g.
 66. The ophthalmic product of claim 61, whereinthe polyester has a Tg of 100 to 120° C.
 67. The ophthalmic product ofclaim 61, wherein the polyester has a Tg of 120 to 140° C.
 68. Theophthalmic product of claim 61, wherein the ophthalmic product is chosenfrom nonprescription eyeglass lenses, prescription eyeglass lenses, andsunglass lenses.
 69. The ophthalmic product of claim 61, wherein theophthalmic product is chosen from nonprescription eyeglass frames,prescription eyeglass frames, and sunglass frames.
 70. The ophthalmicproduct of claim 61, wherein the ophthalmic product has a refractiveindex ranging from 1.54 to 1.56.
 71. The ophthalmic product of claim 61,wherein the glycol component of the polyester comprises 40 to 55 mole %2,2,4,4-tetramethyl-1,3-cyclobutanediol residues and 45 to 60 mole %1,4-cyclohexanedimethanol residues.
 72. The ophthalmic product of claim61, wherein the glycol component of the polyester comprises 20 to 40mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues and 60 to 80mole % 1,4-cyclohexanedimethanol residues.
 73. An ophthalmic productcomprising at least one polyester composition comprising at least onepolyester, which comprises: (a) a dicarboxylic acid componentcomprising: i) 70 to 100 mole % of terephthalic acid residues; ii) 0 to30 mole % of aromatic dicarboxylic acid residues having up to 20 carbonatoms; and iii) 0 to 10 mole % of aliphatic dicarboxylic acid residueshaving up to 16 carbon atoms; and (b) a glycol component comprising: i)20 to 40 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; andii) 60 to 80 mole % of 1,4-cyclohexanedimethanol residues, wherein thetotal mole % of the dicarboxylic acid component is 100 mole %, the totalmole % of the glycol component is 100 mole %; and wherein the inherentviscosity of the polyester is from 0.35 to 0.75 dL/g as determined in60/40 (wt/wt) phenol/tetrachloroethane at a concentration of 0.5 g/100ml at 25° C.; and wherein the polyester has a Tg of from 100 to 120° C.74. The ophthalmic product of claim 73, wherein the inherent viscosityof the polyester is from 0.50 to 0.68 dL/g.
 75. The ophthalmic productof claim 73, wherein the inherent viscosity of the polyester is from0.60 to 0.75 dL/g.
 76. The ophthalmic product of claim 73, wherein theophthalmic product is chosen from nonprescription eyeglass lenses,prescription eyeglass lenses, and sunglass lenses.
 77. The ophthalmicproduct of claim 73, wherein the ophthalmic product is chosen fromnonprescription eyeglass frames, prescription eyeglass frames, andsunglass frames.
 78. The ophthalmic product of claim 73, wherein theophthalmic product has a refractive index ranging from 1.54 to 1.56. 79.An ophthalmic product comprising at least one polyester compositioncomprising at least one polyester, which comprises: (a) a dicarboxylicacid component comprising: i) 70 to 100 mole % of terephthalic acidresidues; ii) 0 to 30 mole % of aromatic dicarboxylic acid residueshaving up to 20 carbon atoms; and iii) 0 to 10 mole % of aliphaticdicarboxylic acid residues having up to 16 carbon atoms; and (b) aglycol component comprising: i) 40 to 55 mole % of2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and ii) 45 to 60 mole% of 1,4-cyclohexanedimethanol residues, wherein the total mole % of thedicarboxylic acid component is 100 mole %, the total mole % of theglycol component is 100 mole %; and wherein the inherent viscosity ofthe polyester is from 0.35 to 0.75 dL/g as determined in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/00 ml at 25° C.;and wherein the polyester has a Tg of from 120 to 140° C.
 80. Theophthalmic product of claim 79, wherein the inherent viscosity of thepolyester is from 0.50 to 0.68 dL/g.
 81. The ophthalmic product of claim79, wherein the inherent viscosity of the polyester is from 0.60 to 0.75dL/g.
 82. The ophthalmic product of claim 79, wherein the ophthalmicproduct is chosen from nonprescription eyeglass lenses, prescriptioneyeglass lenses, and sunglass lenses.
 83. The ophthalmic product ofclaim 79, wherein the ophthalmic product is chosen from nonprescriptioneyeglass frames, prescription eyeglass frames, and sunglass frames. 84.The ophthalmic product of claim 79, wherein the ophthalmic product has arefractive index ranging from 1.54 to 1.56.